Not that I have much experience onboarding but I would actually send them through the primal route. Easy onboarding and a quick wallet setup. Then they can get more technical as they go from there and move to other wallets and freedom tech and go as deep as they like.
Discussion
I'm halfway debating trying to push him in the route of a Shopify site with a BTC pay server. That way he can accept both Bitcoin and fiat, but also advertise on Nostr
Sounds solid.
Another route would be setting him up with phoenix wallet set up a lightning channel and you can help him by hosting phoenixd and set that up with btc pay
this is what I was gonna suggest. lots of options on how he can cash out as well. Shopify is a little more expensive, but it has a lot of functionality for someone just wanting to sell stuff and maybe get some Bitcoin for it.