I'll suggest you start as a replacement player in a game or two first, just to get a feel for the game mechanics.
"24 Hour game patch 4" sounds like a good choice for you (just guessing, but it might be worth a try
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When you have the basics down; try join the KOTH league for some fast and furious one-on-one action
As for starting your own game: You set up the basics at PBW. When you have enough players, you download their empires and create the game on your own computer. Upload the game to PBW again and everything is (more or less) handled automatic from there. Getting players are the tricky part, so unless you have some friends lined up, advertising here will be your best option.