Hello and welcome to Iwaku, Sora!
I'm Kitti and it's good to meet you.
Out of curiosity, how did you find our site? :D
Oh, but since you're new to us, I would like to show you some useful places:
is where you can sign up for the roleplays found in Modern, Scifi, Fantasy, and sometimes Mature. Generally, they will have you post a character sheet in their thread, a new sheet for each roleplay! You can also start signups for a roleplay of your own here.
is where you can find jump in games, which typically have no sign up thread. You just start posting!
These links aren't nearly a full scope of the site, so you should definitely look around for yourself, too!
If you need any help, please feel free to ask. :]