Use Magic Device allows you to use magic items you wouldn't normally be able to use. Anyone can use wands that cast spells from their own spell lists (for example, as a Bard you could use a wand of Cure Light Wounds) but you need UMD skill to use wands and scrolls from other classes.
In terms of character build, I advise you to focus on something. With your "+2 to one attribute" Half-Elf bonus, you can have one 18 stat. Put it in Strength so you can be an effective front line melee guy, or put it in Dexterity and be an archer (and take archery feats like Point Blank Shot and Precise Shot), or put it in Charisma and be an effective caster (maybe in combination with a Spell Focus feat) - Charisma makes it harder for enemies to make saving throws against your spells.
In Pathfinder, if you try to be good at everything, you'll probably wind up being good at nothing.
Before I can give you some advice on what skills you should take, I believe it's a good idea to see what everyone else in the party is playing. But even without that information, I can tell you that Perception is a godsend, and something you're going to roll every session.
Do you think it's something I need to put points in at level 1?
Probably not - you're unlikely to get any good magic items early on. You can always put a bunch of skill points into it at a later level.
You're a Bard so you've got plenty of skill points. Take some knowledge skills and at least one type of Perform (Sing and Oratory are good since they don't require you to carry a piano about with you everywhere). Note your 'versatile performance' skill which kicks in at level 2 - it will allow you to substitute Perform for some other skills, so you don't need the ones your Perform will cover.
(Also, note that you can only put one skill point in each skill at level 1.)
Spells like Sleep (powerful at low level but takes a whole round to cast) and Charm Person (more for out-of-combat use) are pretty good. There are other similar spells but they're often not very powerful - they cause one enemy to waste a round (or take some minor penalties) IF they work and you have to sacrifice a round and a spell to do it
As a level 1 Bard you'll only be able to cast two spells a day, and this relies on the GM throwing things at you that these will work on - undead are immune to mind-affecting spells, for example.
If you have Charisma 18 and Spell Focus: Enchantment, then enemies will need to making a saving throw of 16 to not fall asleep when hit by Sleep. If you have Charisma 14 and no spell focus, they'll only need a 13. Typically that might be the difference between a fifty-fifty chance of it working and a two out of three chance of it working.
I played an archer bard using the arcane duelist archetype in our Carrion Crown game (which then progressed into home brew to level 20 and Paladin in Hell). This was some 5 years ago, and we didn't have access to all of the books even then, so he was fairly vanilla.
As a human, he started off with point blank shot, precise shot, and a short bow. Eventually went up to bard 11 before taking 5 levels as fighter. Feats at level 12 (bard 11/fighter 1) included Deadly Aim, Great Fortitude, Manyshot, Rapid Shot, Snap Shot, and Weapon Focus (shortbow).
Ultimately ended up with bard 15/fighter 5 and he was a good, well-rounded character who was able to buff the party, heal a little, had good skills, and could land a bunch of ranged attacks for solid damage. I was pleased with how he turned out. Good luck!
welcome to pathfinder. I don't know much about shadowrun (so no clue how different the systems are). That being said I'm not entirely sure I would suggest a bard as your first character if you aren't familiar with D&D 3.5 or pathfinder. That being said...
I'm going to assume your rolls can go anywhere you want them.
Half-Elf
Str-16
Dex-16
Con-13
Int-12
Wis-12
Cha-13
These are the stats I would go with. This will get you the base casting you need and will let you be competent in melee or archery and switch between the two. Alternatively, you could go more str if you only want to melee.
Archery- If you want to use a bow you need str for extra damage. Dex is important for hitting. You could go 14 str and 18 dex if you want to max out your hit rating.
Favored class bonus. Each time you level up in bard (and as a half-elf a second class of your choice) you get either 1 health or 1 skill point. If you are using more than just the core rulebook you could get one extra round of bardic performance instead, but I'll just talk about the core rule book for now. I would go with a point of health as you already get 7 skill points per level and are a bard.
7 skill points. 6 for being a bard 1 for your 12 int. pick some skills you want to have.
Perception- is the most important skill in the game. You will use this constantly.
Perform Oratory- This is important because starting at level 2 this becomes your diplomacy and your sense motive skill. In my experience these are the next most used skills. Maybe bluff, but you can get perform act and use that as your bluff and disguise check later.
Beyond this is up to you.
Knowledge- it's always fun to have a few knowledge checks, but they are very campaign dependent.
Acrobatics- if you like to move around and provoke a lot of attacks of opportunity, this can save you some.
escape artist- This can help you get out of grapples if the campaign is using them heavily.
Swim/Climb- if a campaign will need them your DM should tell you. Generally they aren't that useful.
Stealth- stealthing as a group is near impossible, but being able to sneak one member past a guard-post could prove valuable.
Sleight of Hand- useful for stealing or something specific. I'd generally avoid.
As a bonus for half elves you get a bonus 2 to one skill. I would pick perception or perform.
Feat- you need to pick one feat. I would suggest something that you intend to fight with. If you want to melee, weapon focus is a good start. If you want to use a bow, point blank shot is your best choice.
Bards are support characters. This means they make other characters fight better. So be prepared to not "shine" in combat directly yourself. You're going to be making everyone else a whole lot better, though. This includes the druid's animal companion and any creatures s/he summons. So you will be a great force multiplier!
So when combat happens, your first turn will probably be starting your Bardic Performance so everyone can fight better.
Then, you have to decide what you want to do in rounds 2 through 10. You have a few options.
1. Melee combat
2. Ranged combat
3. Cast spells
1. You either have to invest in Strength and/or invest in Dexterity AND take the Weapon Finesse feat, so you can be good with rapiers and daggers and stuff.
2. You will want to invest in Dexterity, which is a really good stat (it affects initiative, Reflex saves, Armor Class, fun skills like Acrobatics, Stealth, and Sleight of Hand, ranged attacks (and some melee attacks if you take Weapon Finesse)). Feats to consider: Point Blank Shot (a prerequisite for lots of archery feats), Precise Shot (it removes a lot of archery penalties), Rapid Shot (it lets you shoot twice per round, but at reduced accuracy).
3. You only get a couple spells per day at 1st level, so you can't even cast spells every round in your first fight of the day. So you probably want to use options 1 or 2 as your back up plans when you either run out of spells or you want to save spells for later.
If you plan on switching between melee combat and ranged combat a lot, you might want to consider using a throwing weapon, like javelins. You can throw javelins first, then draw a sword and hit things with it. You can even use a shield when doing this.
* * *
But fortunately, Pathfinder isn't just fighting. Bards really shine in social situations. A lot of your class skills are based on stuff like talking to people (lying to them with Bluff, persuading them with Diplomacy, scaring them with Intimidate), listening to people, and knowing stuff (the various Knowledge skills, Linguistics to speak lots of languages and make & break codes, Spellcraft to know what enemy spellcasters are doing). You can also choose to be an infiltrator, using skills like Acrobatics, Climb, Stealth, and Swim to get into places and explore and scout.
Others have given some good advice on your build, so allow me to offer some more general advice, worth what you paid for it.
Based on my old and limited knowledge of Shadowrun let me point out some differrences.
1. Starting power and growth: In SR you can make a starting street sam who is one of the better gunman in town. In PF the captain of the village can most likely wipe the floor with any level one character. Your level determines a huge amount of your characters power, you have alot of growing to do.
2. Unless your group is using the optinal rule for hero points there is no equivalent to using karma to boost a die roll.
3. Attribute connection to success: rather than indiredctly impacting skills and combat by setting various "pools" your attributes (stats) directly effect your skill and combat rolls.
4. Wound penalties: in PF you (or your enemy) are just as effective at full hp or at 1 hp.
And welcome to the PF community, like you I was thrilled at the helpfulness of folks here when I stumbled in a couple years back, and honestly this is a big part of what has kept me playing this game.
You Said you want to be a Rogue-ish caster. Have you thought about the Archeologist Bard? It trades all the performance abilities for Luck. You pick up some Rogue Talents along the way.
Given your lack of experience, I suggest a bard that uses a melee weapon.
As mentioned above, playing a bard focused on spellcasting requires more experience, so I don't think it's necessary to put your highest ability score roll in Charisma. Strength affects your melee attacks and damage rolls. Dexterity affects ranged attack rolls, armor class, Reflex saves, initiative, and several skills. Charisma will affect your spellcasting and several skills. Constitution will increase your hitpoints (important for melee characters) and Fortitude saves. Wisdom affects Will saves and several skills. Intelligence adds to several skills and the number of skill points you get. I suggest putting your better ability scores into the physical ability scores and Charisma. Since all of your rolls are 12 or higher, you won't have any deficiencies.
I suggest using a rapier and shortbow. The rapier has a high crit range, which means that you will deal x2 damage more often. You can nock an arrow in your bow without spending an action to do so. Ranged weapons like crossbows and slings take time to load, so if you had the choice to load, move, or attack, you would have to choose two of those each round. With a bow you can do all three. If you feel like it, get a whip too. Its not a great weapon, but you are one of the rare characters that knows how to use one.
You skill selection will depend greatly on your personal preferences, what the other characters can do, and what challlenges you think your GM will throw at you. generally speaking though, at level one I suggest Perception, Knowledge (arcane), Knowledge (local), Acrobatics, Diplomacy, Perform, and maybe Stealth, Climb, or Swim. You won't be able to do everything well at 1st level so you'll need to make some choices. UMD can wait, and at each level you can get one or more additional knowledge skill. Skills like Climb and Swim are important at low levels when you will face non-magical challenges, but later on such challenges will becomes less important. Also decide what your first versatile performance skill will be, so you can avoid putting points into the relevant other skills.
You Said you want to be a Rogue-ish caster. Have you thought about the Archeologist Bard? It trades all the performance abilities for Luck. You pick up some Rogue Talents along the way.
With the Fate's Favored trait. This bard is pretty decent in melee, and as a half-elf, you can take ancestral arms alternate racial trait to get a decent melee weapon.
With a Half-Elf, you can take the Varisian Tattoo trait giving you access to starknives; and then you can trade a versatile performance for Cha to damage and attack rolls.