Is it possible to include him on some sort of design / architecture meeting with your team? That might give him enough to think about and learn from while keeping him engaged.
why not do your job, and let him shadow you? Have some faith that he'll ask questions if he's lost.
When I was a teen, I visited my older sister at work one day. I ended up doing stuff like stuffing envelopes for her. After I left, the department hired some assistants to do more of that kind of thing for people in her position so they weren't doing so much admin type tasks.
When I had a corporate job, I did an hour of job shadowing here and there for specific purposes. When in another department, I just watched as they did typical work so I could better understand what they did in a department that supported ours. In my own department, there was more explaining because I was shadowing someone faster and better than me with the express purpose of improving my speed and general process.
At age 14, I was introduced to computers by a friend of my sister's. My sister was in college and I was visiting her. The friend was surprised at how much I was able to grasp given that I had no computer background (this was in the dark ages, when I had a yellow rotary phone and pet dinosaur).
So I think: A) Just letting him watch is perfectly fine. B) If he asks questions or has a specific purpose, you can tailor it some at that time.
i recall doing a couple of days of work experience at a similar age, perhaps a bit younger, where i was parked in front of an old linux machine and left to learn/play with some interpreted language i'd never seen before.
given i was only there for two days, this wasnt going to turn into some ongoing work, i think giving me some hands-on and engaging thing to do - despite it being totally independent to the project they were working on - was probably a good idea. from memory i found it pretty interesting.