Skeet shooting with a pump shotgun is a hard way to start out. You're going to have to try to hit doubles at four stations. Your defensive shotgun isn't meant to be used for skeet.
Get in the same squad as your friend and borrow his shotgun (bet he's got a semi-auto or double barrel).
If you get hooked on skeet shooting, get a decent semi-auto w/26-28" barrel. It's a great sport and very addicting.