If you want a delightful hobby, then I can recommend building your own guitar pedals.
It combines music, electronics, general nerding out (e.g. debating germanium VS silicon diodes), and some visual design if you want to make the enclosures pretty. You might even be able to sell some.
I started by building a kit pedal with one of my kids as a weekend project.
Some search terms to get you started: build your own clone, diy pedal schematics, tag board music effects.
It combines music, electronics, general nerding out (e.g. debating germanium VS silicon diodes), and some visual design if you want to make the enclosures pretty. You might even be able to sell some.
I started by building a kit pedal with one of my kids as a weekend project.
Some search terms to get you started: build your own clone, diy pedal schematics, tag board music effects.