Try and enjoy the outing as much as possible. It's not life and death, so a miss is just that. Lose the target and not the lesson. Its like learning to ride a bike, at the start everything seems to be happening soo fast and seems overwhelming. after a while its all second nature. Shooting will be the same.
Drink regularly, have a snack and most importantly BREATHE.
Enjoy the outing
Let us know how you did and what it felt like