Not a bad idea to wait. Though if he's not going to game, the Ryzen will be better value. You could even go with something like a Ryzen 5 1400 or 1500x. I have a 1600 overclocked and with a decent graphics card, it's great for games. If you aren't gaming, I don't think you'll see a difference, and you'll spend less too.
My dad and I when I was younger started out building computers, primarily because I wanted to game lol. Back in the days when 200mhz was fast. If your kid is anything like me, he will want to game at some point. But I would say get him like a Ryzen 5 1400, a B350 board, and something like a GTX 1050 graphics card for 100 bucks. That way, he has enough power all around to use the system, but also if he decides he wants to game, enough to dip his toes into the water. As well as with a B350 board, those are a decent mid range board, and if AMD is to be believed, they are supposed to support that socket until 2020. So then you should have the flexibility to drop in a better graphics card later or drop in a better cpu in a couple of years. But it would be simple enough to get your feet wet and figure out what you want.
For day to day, you won't see a difference between that and an intel. If anything, I think it would smoother for web browsing or if you get to multitasking.