Not sure how much info you got, so I'm just going by what I can tell you already have.
You actually need to make a new thread in the Sign-ups and OOC section. Put in the story, template, rules, etc. and then wait for others to join. It can be a complicated process because you have to find a way to make your RP unique from the rest of them. That could be hard considering that you're going for a KH RP, but possible.
Take Solace in Night for instance. That guy combined Star Wars of all things. STAR. WARS. At any rate, best of luck to ya. And if you need any aid of any type, just ask one of those requenting this section or just drob a line in the Mentor thread.