I'm new where to start?
Lulu, I'm sure there are other ways to go about it, but here's what I did.
First, I found a game that was looking for a player to adopt an existing character. Before joining the campaign, I asked the GM for permission to "lurk," which allowed me to take my time reading thru threads and following live game play before deciding whether to join. After a while, I then took the plunge and joined in. After that I did my best to be a "good citizen," learning the rules (written and unwritten) of RPoL, and trying to do things the right way, both in my dealings with the GM and with the other players. (FTR, this was very much a trial and error process, and I made lots of mistakes.)
I repeated this process with a couple of other campaigns, so I got a feel for playing on RPoL and for different GM styles. After a while, more gaming opportunities started to present themselves due to the relationships I formed. Which allowed me to get in on the ground floor of some new campaigns, creating my own characters and participating in the OOC "get to know one another" stage with other players.
My four pieces of general advice would be: (1) be patient with GM's - they are human, so their personalities vary widely, and none are perfect - it takes time to discover one's strengths and weaknesses; (2) if you find yourself in a game you don't enjoy, or if your life circumstances cause you to need to drop out of a game, THAT'S PERFECTLY OK, as long as you do it the right way (i.e., don't just "ghost" the game); (3) learn to use the "preview" button to carefully review your posts before publishing; for a lot of reasons, it's far better to get it right the first time than to edit after the fact; and (4) in your campaigns, READ everyone else's posts since your last visit to the site (not just in the game thread but in the OOC discussion and elsewhere), before making a new post of your own; that seems like an obvious thing but it amazes me how many people fail to do so.
Hope some of that helps. Good luck, and happy gaming!