I'm a big fan of Aqua right now personally. Mutiny is continuing to be a great choice. And of course if he crosses past 1m sats, start hodling cold. 

 As for how to sell the garbage to begin with sans kyc, robosats ain't bad, but beyond that someone else is gonna need to answer. 

Hope it helps. 

 Why not use something like Bisq to buy non-kyc BTC and store it for him? 

 I was never able to get bisq to run on my ubuntu machine...will revisit this though, good idea.  

 Alternatively, look for local bitcoin meetups and buy directly from people there. Could set your son up with a lightning wallet like Zeus or Mutiny and then transfer to a cold wallet later. 

Great opportunity to meet bitcoiners in your community, spend quality time with your boy, and teach him how to transact, transfer, and store his corn. 

If not meetups exist in your area, and you’ve got the moxie, consider starting one. 

Whatever you choose, it already sounds like your son has a good father who is setting him up for a strong financial future. 

 BTMs plus a self custodial wallet of your choice is simple and quick to startup (Cake, Bluewallet, Green, Aqua, Mutiny to name a few of many)

Or @bisq or Robosats might match you with a sellers bank account you can just deposit paychecks into (semi-trusted counterparty deal)

Or go straight to timelocked multisig cold savings for now with a test UTXO, figure out the weekly expense wallet later.  Periodically reuse the test UTXO to test the wallet with a self transfer each year or whatever

If the kid is working legally in a fiat jurisdiction, they're already effevtively KYCd, and doing this won't hide the fact that the checks are likely going into bitcoin, but immediately cashing out to self custody what doesn't need to be in a bank is a great habit!