Hi! I'm New and Need Friends! :)
Welcome to the community.
Read the FAQs (upper right hand corner of every page). That will teach you a lot about the site, especially the rules.
Every game here is run by its own GM. The GM controls who gets into the game, posting rate, etc.
To find a game, check out the Players-Wanted forum where most new games are advertised. Each one will have a link to its own forum where you can get the low-down, including what is wanted in an RTJ (Request To Join).
You can also let potential GMs know what yo'd like to play in the Wanted-GMs forum.
If you consult the Game Proposals, Input, and Advice forum, you might get an inside track on upcoming games.
Best wishes. Hope you have fun here.