I wanna make friends!
Well, you're in a good place for it (making friends, that is). This is a friendly place.
WhiteComic has pointed you correctly. I would add that before joining any game with Mature or Adult content here, it would pay to read up on the policies concerning these games and how they are managed here. (Accessible from the FAQs under Site Policies).
You will meet many nice folks here, so don't be too shy. Knock around and get to know the place a bit, and when questions arise, don't be afraid to ask.
Staying on topic and posting in the proper forum are skills always appreciated here, which is why I suggest getting to know the place.
If you eventually intend to run a game, you've just found the best toolkit to organize and manage a game for play-by-post you are likely to find in this galactic neighborhood. Definitely check it out if that's a goal for you.
Have fun. I gotta run. Duty calls.