Not really sure where to ask this, as even the Google answers are very confusing for me.

I’m interested in DIY consumer(?) electronics. For e.g I saw a video of someone buying a used tablet screen, a display board, and made himself a little portable monitor. Or I have a retro handheld, and some people open theirs up, and replace the speaker in it. They buy the actual little tiny speaker from China and put it in themselves.

This stuff is cool as hell how do I learn how to do this?? I know I can look up project guides and recreate them, but I’d eventually like to be able to do my own things (like if I want to make some kind of soldering change?) And I assume that requires more in depth knowledge.