Just like Mike said, the first couple times, you will have some butterflies. My jitters ended as soon as I mashed the gas on my first time down the straight, it turned into pure adrenaline. Leave your car in the pits, and walk up to the stands, just watch a couple cars go. It's intimidating at first, but its far from rocket science.
Just relax, your first run will probably not be very well, but its a learning experience! The best way to learn is to just go out and do it, I'm sure you have a good idea of what to do, so you'll be fine.
A couple of tips:
1.Only a quick spin (1 sec) of the street tires is needed for a burnout(make sure not overinflated)
2.Your first run will suck! Your first run should be for experience, not TIME!. So just launch from idle, and take it easy, see how you do. The track/launching just takes time to "get a feel" for it.
3.Remeber to shift out of first! Some people get so worried about launch they forget to shift, first is over in like 1.5 seconds!. My first time, I almost put myself into a wall by launching too hard. (428 w/ 3.73 and mean shift kit
)
4.HAVE FUN! It's the best feeling in the world..........ok 2nd best