I think the first program I "wrote" (copied from a book into a computer) was in BASIC. Why not start there?
Do a simple "Hello World" program. Have him modify it to say something different. Add logic over time to make it more interactive.
The first programming language I really understood and wrote (not copied) programs in was VB4. I've been getting paid for development for 12 years now, and I've done work in
VB, COBOL, Aion, and Java.
When I was learning Java last summer (on the company's dime), I was finishing the assignments VERY fast, so I challenged myself to write a text-driven blackjack game. I included logic for choosing a single-deck or eight-deck game, dealing cards from the shoe, placing the marker, shuffling and reshuffling, placing bets, splitting, doubling down, hitting, scoring a hand, going bust, dealer logic for standing/hitting and so on. It took me about a week to write. I'd never written a game before, but I realized that good object design was key to making the game easy to write.
One thing I've never done is any kind of graphic programming. Don't know the first thing about it.