Might be worth checking out classic juvenile (meaning "for grade school boys") SF e.g. Heinlein's Rocket Ship Galileo (1947). Penned over 20 years before Apollo 11 yet eerily prescient.
Boys in the grammar phase of development crave detailed descriptions of things and how they work. Basically techie stuff and not too much dialogue.
A bit of clever banter & good-natured kidding, internal dialogue & reactions--sense of wonder, chills up the spine, primal emotions--appropriate to the occasion are good too, just not too frequent or too long.
Vivid descriptions from all senses--sight, sound, vibration, smell, etc.--are indispensable, the more vivid and brief the better.
BTW most "real" boys don't care a whit what color lockers are. Kewl stickers on a locker, that's a different matter.