Easiest solution I can think of is setting up some LED's (
Lume Cube – Strobe Anti-Collision Light (3 Pack) – New Drones, Accessories and Repair) on football goalposts and having the trainees stand varying distances from the posts and fly figure eights through the posts to get a better feeling for how to identify and coordinate the aircraft in night conditions. Easy version of the drill could be keeping the aircraft nose pointed in one direction so the trainees only have to worry about figuring eighting with the right stick. Then once they get good at that they have to do the figure eights keeping the nose of the aircraft pointed the direction the aircraft is traveling at all times as to obtain a in deeper understanding of maintaining aircraft orientation in night conditions. Would require getting permission from the local highschool or facility but I'm sure they would not have a problem with it since the teams not using the field at night anyway. To get the lights up there you'd need a long ladder and some lumecubes (linked above) but it may be easier than setting up your own obstacles.