Hello, everyone! My name's Chris but you can call my Choomie, it's a nickname. I just joined the site a few days ago but I am really unsure of what to do next. I'm almost eighteen years old, and I live in the United States. I began roleplaying at the table at the age of thirteen when I was introduced to D&D 3.5. Inevitably, I found my way to Pathfinder. My favorite games to play at the table include Pathfinder, Star Wars Saga Edition, Star Wars FFG, Apocalypse World, and a bit of Call of Cthulhu.  So yeah, thought I'd introduce myself.
This message was last edited by a moderator, as it was against the ToU, at 13:15, Thu 28 Apr 2016.

Welcome!  "What to do next" can be handled a couple of ways.  In no particular order:
1) Go to Wanted - Players to see what games are being advertised.  If you find one that looks interesting to you, click the link and follow the instructions to join in.  Game Proposals, Input, and Advice is also a good one to check; there won't be game links there, but there will be plenty of people pitching games they haven't started yet to see if anyone is interested in playing.
2) Go to Wanted - GMs and post your own thread telling everyone what you'd like to play, then wait for someone to (hopefully) come along and start a game that fits your request, or maybe just tell you that they have an existing game that works.
3) Click the Browse/Search link near the bottom of the main page.  You can filter by genres and/or systems, as well as whether or not the game is specifically marked as seeking new players.

Welcome Choomie!

Definitely read the FAQs and start-in a bit on the Help in the top-right.

But, at Dr Mindermast stated - definitely check out the Wanted - Players, Wanted - GMs, and Game proposals areas.

They are where most games begin or spark.