If this is your first, the car doesn't really matter.
Best advice I can give is to look ahead. Your head should be turned before the car turns. Like this:
If you are looking at the star, you're not looking far enough ahead.
You might also want to say at registration that you're a newb and ask of there's anyone willing to walk the course with you. Autocrossers are a pretty friendly bunch.
If you have a portable air tank, it's a good idea to take it with you. Otherwise, just up your pressures ~7psi.