Julie,
You will do fine. I was an older mom when our son was born. He went to school with some of the kids I taught. Talk about feeling like a grandma. Once they get to know you they will realize how much you can help them and then its vice versa. They too love to give advice and if you're willing to accept it you will learn a lot about the young generation.
It is scary at first though and we were uncomfortable a lot. One of my husbands former students is our neighbor we have found we both enjoy scrapbooking. Its a small world.
Maggie