I know it's been a lot of trial and error so far. Once things are dialed in correctly it really will be easier just doing routine temp checks and all.
You're doing great. It's awesome to see someone being so proactive to wanting to make sure the animal is well taken care of. It's a great gift and learning experience to your son as well. I used to work retail pet shop so I've seen a lot of parents just do the half-hearted "it says for snakes." And just buy the cheapest starter kit or an animal that just is not appropriate in any way regardless of what I said.
You'll be teaching your son so much more with this by showing that care for other animals matters and they aren't a disposable thing