Keep your I.D. with you at all times, especially if you're an upperclassmen. Have your parents sign the form that says you can have Tylenol, Asprin, etc. Keep track of all belongings. Don't forget computer login password, along with login name. If you forget it you can ask in the media center and they'll look it up for you, but it's a pain to go ask when you've got class time in a lab.
Stuff is sold in the lobbies during the year such flowers, cookies, and pop.
You can go to dances with friends or dates. Use phone booth adjacent to the office to make calls, or ask to use teacher's phone. There are pay phones by the gym and in the lobby if you don't like standing in line and have change to spare.