Good luck Dimitri!
What we do when demonstrating Subbuteo over here, is just make sure we have an extra table or two set up, and when people come take a look at it we get them to physically try it out.
We never worry about the specifics of the game (such as timing etc) all we do is let them play around with the game and get a feel for it, and if they ask questions we answer them and we also give our contact information so that we can get them all the details.
Have fun showing it off!
