do i need to roll dice to hit a npc with a fire bolt, what do I need roll against to do so or is it like magic missle and no roll to hit needed?
Should say exactly what you need to do in the description of whatever fire bolt is.
For example, Fire Bolt from the Fire Domain:
Fire Bolt (Sp): As a standard action, you can unleash a scorching bolt of divine fire from your outstretched hand. You can target any single foe within 30 feet as a ranged touch attack with this bolt of fire. If you hit the foe, the fire bolt deals 1d6 points of fire damage + 1 point for every two cleric levels you possess. You can use this ability a number of times per day equal to 3 + your Wisdom modifier.
So that would be a ranged touch attack.