Best sources for theory?

Hello,

I have been diving into photography as of late, however I cannot find a lot of concise materials on photo theory and theory of photo edits. I usually find small blips, articles and alike, but I would love for either long course, those more comprehensive texts are usually quite old and as a newbie I cannot wager if that's okay or not (if they're not outdated as of today)

As such I would like to ask for guidance for material on :

Photo theory

Anything from artistic theory I may find useful for understanding art (I have literarily ZERO artistic education and it's overwhelming as to where to start, I never have read single non-scientific book in my life and watched maybe ten movies)

Theory of photo edits, something to help me navigate what each settings mean

Rawthreapee sources? I know they have documentation but is that the best there is?

Thanks everyone for their two cents