Don't cut weight for your first comp.

Enjoy, don't be pressured to win. You'll most likely lose, but learn a whole lot.

You will spaz. Your opponent will spaz. I remember my first comp, the score was 15-13. You can imagine how much scrambling and spazzing was involved. So the key here is really, try to slow things down and hold on to points if you can't submit people proficiently yet. (Assuming it is a points comp.)

Main goal is to learn. Second, equally impotant goal is to be injury free. Since your opponent is spazzing 100%, injury rates in comps increases a lot. Especially in whitebelt. Do Not hesitate to tap. Do not hesitate to let go of positions. I have seen a number of first timers get their elbows dislocated or going to sleep cause they are too stubborn to tap. Remember, submissions here are applied fast and 100%- not tapping is not worth it