Treasure the moments. Seeing deer and getting home safe is what it's about. Shooting a deer is a rush, but focus on learning and companionship
and sportsmanship. Don't demand too much of the kid. I know that we get all excited by deer and tend to focus on that. I took all four of my kids to gun safety training and hunting. Time very well spent. My son helps me hunt now. Be patient with him and yourself. Remember they haven't run out of deer but you can't replace a person. Good luck and think of the first time as a scouting trip with the benefit of taking game if you can. Also deer often do the unexpected and can hide in plain sight sometimes.
I think I would go with a ground blind. If nothing else take two folding chairs where you will comfortable and build a quick blind around it. Use whatever is available, there are some real inexpensive fabrics at most of the chain stores that you can just hang up. The boy will be a boy and try as you will he is still going to fidget. A ground blind will offer some cover for his movement.
He will need a good rest for the rifle if nothing else use a forked stick to steady him up a little.
I have 3 boys 5, 8 ,12 and I take them all hunting safety 1st but make it fun. I've found that it is not about seeing deer as spending time with their parents. With that in mindI take them after I've put some meat in the freezer and I reserve some prime time for myself to hunt horns. good luck
SAFETY FIRST!!!!!!!!!!! And the rest is all about making good memories. If you are going to get upset at the boy for being a fidgety boy than stay at home and don't ruin it for him. I have two very active little girls that have been hunting with Daddy since age 3 and over time they learn if taught in a good way. The quiet game works very well as everyone else said. My girls are 7 and 8 now and they get on to me for moving around in the stand. It's all about the fun and future of the hunt but be safe so that next year you can repeat you good times.