Not sure that I could talk for 40 minutes on drag ......any hints or tips also appreciated
All sorts of ways. Although there are a zillion types of drag, you can emphasize that *all* aerodynamic forces derive from one of two sources: pressure differences and skin friction.
Induced drag, for example, is due to pressure differences around the airfoil.
People often attribute powers to lift that in reality depend on drag. Want to increase your glide range? Reduce drag, not increase lift. Want to climb more steeply? Reduce drag, don't increase lift. Want to decrease the influence of ground effect? Increase drag, don't worry about lift.
Giving them good information is a good start, but forcing them to integrate what you tell them into how they think about flying is something else entirely. You need to hit the same points over and over and over again.