Nice looking rifle. I am sure your son is pleased. One of the things you rarely ever read about is techniques for children shooting their first scoped rifle. First and foremost use a rest to sight in the scope, which can sometimes be a bitch with a pellet/ BB rifle. Not all those little pellets / balls are made to a precise standard.
Don’t make the mistake of trying to sight the scope in over 25 yards, usually 15 to 20 is better for velocity and accuracy. Without a lot of experience, a child will have a hard time making accurate shots over that distance. Remember, pellets / BB’s are very sensitive to wind and will drift on you like a racecar.
Start him shooting from a rest, keeping a reticle from moving is almost impossible without a rest or sling. Even adults will become “lost “in the reticule, trying to hold it perfectly still and jerk the shot. Just explain that without a solid rest, there will always be some minute movement. Experienced shooters will acknowledge the movement and simply make the shot when that “movement” matches their breathing.
Finally, buy some “splash targets, which when struck give an immediate hit placement. You can buy small ones with various critters on then, usually with a black background and when struck show a green or yellow hole. Even adults like immediate feedback. 1200 FPS? That is no joke, may have to get one myself. Be safe, have a great time.