I'm new to everything, this website and RP in general! HELP!
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.