Hey, it's awesome to read that you didn't know what you were doing, you studied the problem and figured it out. GREAT JOB! I have one tiny suggestion - in addition to carrying spare tube, patch kit, pump, and tire levers, carry a tiny sliver of soap, because that is a great help when you are working your fingertips to the bone trying to slip the tire over the rim, at the final stages of putting your tire back on the rim after you've repaired/replaced the tube. You just rub a little soap on the rim and the damn thing pops right into place with much less fuss.
As for your son learning to keep his helmet on, ha ha. Good luck. My kids were so used to seeing their parents always wearing helmets that they never questioned it, but if your guy does, he'll probably adjust, given how much fun riding is.