I see you live in South Florida. You may want to check your laws regarding BB guns. Most communities, and a lot of counties, have a 'No shooting' law in effect. That's another thing most kids don't think about. It's fun to run around the neighborhood playing 'shoot my butt if you can', but some neighbor is going to call the cops, and than the fun begins. Another point that needs to be addressed is where he can and can't take a 'BB' gun. One place that is definitely out of bounds is putting it in his backpack and going to school with it. It happens a heck of a lot more than you might think it does. For every time you read it in the paper, there is another 100 that doesn't get caught.
All that being said, I think it is great that you are being willing to see that he has some exposure to the shooting sports. There is nothing that I can think of that is better for a kid to get into. My sons and grandsons all love the sport. This is a picture of my 13 yo grandson having a fun day at my place.