Hey there and welcome to Iwaku, Gleek~
I'm Kitti and it's good to meet you.
The Community 101 is vastly helpful indeed!
Pushing buttons is also highly effective. XD
Since you're new and requested it even, I have some links to help you navigate too!
This 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.
This is where you can find jump in games, which typically have no sign up thread. You just start posting!
If you need help or have questions, feel free to ask.