Can someone please explain Roleplay sites to me?

Basically what tu do in a roleplay is tu create o claim a character and tu portray him/her. tu have conversations with other characters, etc. At least that's how most roleplays go...
i recently just started my own supernatural roleplay if you're interested in joining, we'd be happy to have tu :)
www.supernaturalroleplay.piczo.com
yeah i checked out the site tu signed up for and it seemed pretty confusing..
but mine is a LOT simpler to follow in case you're wondering :)