Hardware and your intentions on this lad aside, the question still stands: why not simply ask him if it would be appropriate to buy him a meal?
If he says yes, then go for it.
If he says no, then…I dunno, bring him a home-cooked meal, invite him over for one, arrange to meet up at a tasty Dumpster to share found food.
Or do something free that doesn’t involve a paid-for event or food. A fair, museum, hike, bike ride, state park, like that.