Welcome!
It may be alarming at first that your posts don't show up as soon as you post them. This is a way to make sure that new members don't spam, or are robots. Once you reach approximately twenty posts, you should be able to post normally.
Like the others have suggested, it would be a good idea to familiarize yourself with the Site and Roleplaying guidelines before you begin roleplaying. This way you don't unintentionally break any rules while roleplaying!
This site offers a diverse selection of roleplay forums. There is, of course, the Main roleplaying section where you'll find everything you need to role play as a warrior cat, like in the books; the alternative roleplaying section at the bottom allows for "Fan-Clans" (clans created by fans that don't merge with the main rolepay and allow for powers, abnormal cats, etc.) There is also the "Other" roleplaying section that allows for roleplays involving everything from vampires to hamsters.
Each forum has their own "resources" for characters, such as biographies or family finders.
Be sure to check out the OOC board for interesting forum games, creative art, and more!

~Rubinaito