Congrats for taking on that responsibility!
Advice? Keep a cool head, explain why someone can't break the range rules, be vigilant, teach, don't argue, and keep safety of the utmost important.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)