Any child under the age of 14 --- while at the shooting range --- should always be accompanied by an adult.
Give the kid some decent eye and hearing protection. Not just ear plugs...but ear plugs and ear muffs.
Buy the kid a 22 rifle that will fit him. Don't start the kid with a pistol, until he has learned the fundamental's of firearms safety with a rifle.
Shoot reactive targets...like metal spinners, Necco Wafers, balloons, pine cones, etc, etc.