Agreed that keyboards are a good early project. To add to that, if you play video games, leverless arcade controllers can be a fun build also. Pretty similar overall as far as parts and shape, but the firmware they run (stuff like GP2040-CE or HayBox) make them act as controllers instead of keyboards, and they can even work on game consoles. Specifically I'd recommend the Flatbox rev 5[0] and the Open-Frame1[1].

[0] https://github.com/jfedor2/flatbox

[1] https://github.com/GregTurbo/Open-Frame1