Dear Dave, 

As long as the prom is not going to be a major obstacle for you, if it is just a dance and some healthy fun with your friends, I do not think there is any problem in going to it. You know the type of friends that help you, and the type that can lead you into problems. You know what is right and what is wrong so, 'keep your head on', choose the right friends, do the right things, be careful with the drink, and have an agreement with someone you trust that you will watch out for each other especially if something unforeseen happens (like a 'friend' wants you to try something he brought with him?). If you are uneasy about the prom for some reason, then don't go. 

God bless.