How do I get a USCF Rating

Hello I have been playing chess for a while now. I played in Iraq for a year. I read books and expanding my knowlege on chess. I guess I am around a 1500-1800 rating depending on the day. I still have alot alot to learn. I played a guy today on msn gaming zone and he beat the socks off me. He said he was rated 2200. He threw all of these gambits at me and I had no answer for them. I just want to start playing in tournments. I need to get a rating but I have no clue on how or what to do. If anyone could help me I would be very thankful.