The first concert I ever went to was Roxette when I was 13 or 14 (don't remember!) and I went with my best friend. I told my parents that my friend's mom would go to the concert with us, because I knew I wouldn't be allowed to go otherwise, but in reality she only dropped us off and picked us up afterwards. My parents still don't know... ssh!
Oh, and having my first beer in a seedy joint in town, and being all panicky and eating breath mints so the parents won't find out their little girl has been drinking! Ah, to be young again!