Like I said, I'm new to this website and new to RP, I've been told that RP is really fun so I thought I would give it a try, the only problem is, I HAVE NO CLUE AS TO WHAT I AM DOING!! I need some help. BAD. If anyone has any tips or advice, it would be much appreciated. Thank you!

Welcome to our weird and wonderful family.   Please make yourself at home, and ask any question you'd like.  :)

First, go ahead and check out the FAQ section. That should help immensely.
The forums will tell you a lot as well.
Wanted-Players shows what games are currently "hiring".
Wanted-GMs is where you can post your requests for games.
And the rest are great for meeting people and just chatting about various topics, with Community Chat being one of my favorites.

Don't worry, we're here for you.

There are a lot of different rules systems, most of them specific to a particular genre, like fantasy adventure or horror in various flavors or post apocalypse/zombie and many more. You might want to do some web surfing of 'role playing game' and see where that takes you. Specific searches on Dungeons and Dragons, GURPS, Savage Worlds, Vampire: The Masquerade, All Flesh Must Be Eaten will also get you down the rabbit hole.

There is also free form gaming, where rules don't specifically dictate mechanics for character generation, conflict resolution, etc. Many view free form as cooperative storytelling, rather than gaming.

You can wander around a lot of games here, as long as the threads are open to the public, and get an idea of how it all works.

To answer the general question of "what do you do," hopefully this explanation helps: you know those times when you're watching a movie or tv show and yelling at the character who's about to do something dumb, telling them what they should do instead?  Roleplaying is like that, except that the character actually listens and does what you say (because it's your character, and you control them).  You dictate what they say to the boss or the ex or whoever, you dictate whether or not they open that door that you just know has something horrible hiding behind it, etc.  Then the GM (game master - the person running the show) tells you what happened, you respond however you'd like, and it goes on like this as long as it's fun.