The first time you get on their bike, rev the shit out of it and drop the clutch... the little 250cc bike will do a little wheelie. Then you can be like, hey, it is my first time on a bike and it was an accident.

Don't do this later in the day or they will get pissed and kick you out!

Serioulsy though, just have fun with it. You will learn something even if you have been riding for a while and it is really easy.