Comment by Terretta

This is a great suggestion.

Although, I'm not sure you should start writing software by debugging code that doesn't work, or electronics by fixing something broken.

I think assembling some parts to make a basic thing that works is better.

So first, this book, and then find an equivalent of the 70s and 80s Radio Shack (US) or Tandy (EU) electronic breadboard and parts "build anything electronic" kits.

Then build stuff. Not Arduino stuff, more basic. The things those kits suggest making. Understand why they are the parts they are, in the wiring circuits they are.

Then tweak those to "make your own" to see if you know what the parts are and do and how they combine.

THEN start seeing if you can debug what's broken (and maybe tap into the nothing-but-YouTube suggestions here when it gets to specific things to fix, where seeing can be helpful).

RadioShack/Tandy used to have a series of handbooks like the "Getting Started in Electronics" book but focused more narrowly on classes of things you'd want to repair with both theory (how it works) and practice (therefore what to debug). They were blue covers and quite plain, if I recall.

You don't need courses, but readable/absorbable references to theory and practice for beginner tradespersons are actually great.