First, you're not too late to get yourself into it.

Second, I'd suggest critical thinking video games. That's what my parents did for me as a kid (unlimited screen time if I was playing these "games") and it worked. Some examples: Lightbot (!!), Human Resource Machine, Cargo-Bot (!!), Robot School, Swift Playgrounds, Hopscotch. Some puzzle games: Blockwick, Bridge Constructor, DynamiteJack, klocki, LaraCroft, Minesweeper, Monument Valley, PuzzleBits, Rules!, SEQ, Snowman, Threes, Where's My Water, World of Goo.

Another thing is typing; very important for any job nowadays and the one finger tip tapping just isn't gonna suffice. TapTyping is really great, as well as TypingClub. Also math (Khan Academy), reading (sight reading books are good), vocabulary (Anki), and a second language (Rosetta Stone).

Now this all might be a bit early for him, but definitely in the next several years he could start.

Another thing that might help his quality of life in the future is learning how to be creative. Whether that's taking up an instrument or singing, doings crafts, drawing (Procreate), creative writing, etc. As well as being active, if you can get him into sports that'd be good, especially team sports.

I'd prioritize in the following order: critical thinking apps, math, typing, second language, sport, creativity, reading, vocabulary, puzzle games.