Try a few different launch RPM and see what works best for the conditions that day. Don't get too nervous or worked up about your first time at the track. You have an A4, so you're pretty much guaranteed a respectable time.
Since you're on street tires, make sure not to go WOT off the line or you'll spin too much. Once you get out of the hole, keep the pedal at WOT for the rest of the run. The A4 makes the rest of the run a piece of cake.
Oh, and since it's your first time, make sure not to slam on the brakes after your pass. Ease into them and you'll have plenty of room to slow down for the exit.