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 nostr:npub1sqn6rpml88nq8khuvvneuqztfmvalpsarr8grkwy837hzdw63ajs6t5net 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!