You will have a blast man. I had my first SCCA one last weekend. It was awesome. Like the others have said, embrace the noobness and just ask questions. I found that just about everyone was willing to help me along the way.

Honestly, if you can, find another s2k'er that has some experience. I found ITR0064 and he rode along with me for each of my runs. He helped me understand flaws of my driving and just the overall basics of autocross. It was kind of like one on one driving school. It was awesome. He was a nice guy, and I'd say the s2k community is full of these people at most events. But anyhow, I learned a lot about my car and overall good driving techniques in general. I can't wait to do some more.