Should I Be Nervous?

This may sound to simple but just be yourself. He must enjoy your company and style so they should too. And just the fact that you care enough to ask for help says that you care and will act appropriately. Good luck and just have a great time!
 
PS The big sister in me has to say just take it slow and easy. Don't rush anything, you still have all the time in the world.

Just be yourself  don't let your nerves get the best of you and you will be fine be confident ,not shy

I thought all the answers are good ones. I would  find out where you will be going and ask the other female what she will be wearing. You want to be comfortable and 'fit' in with the others, and have a good time. I will reiterate, relax and be yourself.

If you both have been dating for two months you truly should be alright. Hate to sound like a repeating person after others but these people have given really good advice. Just be yourself, and most certainly just ask what is appropriate for the occasion and then from there give it some prayer. You should be in great shape then. These folks are right, you are young and have all the time in the world! :) Have a good time.

I would be nervous but u shouldn't be

I guess it's normal to be a little nervous. Just be yourself and have a good time.