First of all, welcome! We hope you like it here! :)
The big question is what exactly you're looking for when you say "I need help." Are you just looking for a guide to navigating the site? Are you looking to cultivate some friends here before doing any roleplaying? Do you want to get into an RP and get writing as soon as possible? Are you raring to fire up an RP of your own?
I won't know how to guide you without some more specific direction from you, but I can give a few general starting tips. The bulk of the activity here happens on the forums. If you wish to join an existing RP, pop into a themed forum that interests you (modern fantasy, sci-fi, whatever) and look at what's there. Most RPs keep their character signups, story questions, and idle chatter in a separate thread (usually called the OOC thread) in a subforum of the forum the story thread is in. If you wish to join an RP, check their OOC/signups thread before you just leap into the story. That's why most story threads are tagged with "See Plot": their GMs want you to read up on any pertinent information and have your character approved for the plot before you hop in.
While story threads only have tags indicating whether they're open or not, you may notice that OOC/signup threads have tags that can help you narrow down RPs by subgenre. Whee! If you don't know what you're in the mood for, go check out the Global Signups & Plot List. It's not a true forum, but a meta-forum that contains the listings from all of the different genre forums' OOC sub-forums.
As far as I know, jump-in RPs typically also have OOC threads for banter and plot discussion, but you can leap right into the story thread with a character instead of needing to sign up. I don't know if that's your thing, but hey.
This was probably kind of a rushed beginner's guide, so do please ask me or anyone else if you have further questions! ^^
