I'm assuming you don't mean the in-development MMO "Pathfinder Online" but instead would like to get into tabletop gaming using the Pathfinder rules but can't get an RL group together.
Here's the first suggestion - Go to your local game shop. Almost every game shop has a board. Now, I'm talking about game shop as in TCGs, miniatures, tabletop games, not your local gamestop. On this board, people will post looking for new members for their local tabletop games, or people can put up notices that they are looking for a group. If you can't find it, talk to the guy at the counter and if, somehow, they don't have one? Suggest it and ask if you know of any groups looking for members. A lot of gamers like to hang out at those places and and they overhear things. A lot of them also run local events where you can get your fix. Now, I live in a tiny town in the midwest, the nearest game shop is a 45 minute drive - that type of solution wasn't for me.
The next option I suggest is roll20. Go to roll20.net and make an account - it's free unless you want to subscribe. Roll20 is an online tabletop program where you can play with other people online. You have one player who makes the content, the maps, the encounters, everybody else can control their tokens, make character sheets. Basically, a virtual grid and tabletop and handles dice rolling. However, for this you will almost certainly want to get a headset - most groups play on voice as it's much quicker and easier.
Roll20 is great for not just pathfinder but other systems if you are interested, but understand not all the groups there will be good - just like real life. You'll run into your share of powergamers and killer GMs and, quite simply, groups you just simply don't mesh with before you find one that sticks. Thankfully, people can advertise their game and there is a tool to allow you to search for game type, when the game takes place (so you can keep it in your schedule) and stuff like that. You then post and hopefully the GM will get back to you. When my RL group went belly up, I found a few players there and we've been playing every week for going on a year and a half now.
The one thing you need to know though, not every game is going to be pathfinder society. You'll find high powered games, low fantasy, heavy house rules, custom settings, whole works. That means expect to create a new character for that GMs game.
Otherwise, good luck mate.
There is play-by-post section right on this very forum.
Just keep looking! There are new groups looking for players all the time on these forums as well as the Roll20 forums!