Um, hi there!
Hey, welcome aboard!
There are plenty of freeform roleplaying games here, you don't have to make the jump to dice-based RPGs if you don't want to.
But, play-by-post roleplaying is kind of like an IV-drip of RP. You'll have plenty of time, usually, to read up and understand what dice you need to roll and why.
You should see two forums in your list, "Wanted - Players" and "Wanted - GMs".
The players wanted is where GMs list their games needing players. Browse, find games that interest you, pop over to the game, and you should see a "request access" link, which will allow you to message the GM of the game, you can ask to join there.
"Wanted - GMs" is where you go to request a game, if you can't find what you want in "Wanted - Players". It is pretty self-explanatory.