> I still don't know how or why to take proper notes

I find that there is some element of ritual to "proper" notes. Its personal, and everyone differs. Any given system may sound logcal and sensible, but its most important that you write something, anything. Everything else doesnt really matter. I like to use real paper and pen, and start with a wide ruler drawn margin on the left (of course, you can buy paper with this. I prefer to do it by hand. It feels right.) and the date and subject at the top. Then I put keys on the left (page numbers, question numbers, subtopics, speakers in a meeting) and values on the right (insights, things that seemed cool, the steps of a particularly tricky bit, definitions of words)

I put a dash before tasks I have to do, and a question mark on words or concepts I heard but didn't understand and I need to go look up later.

Literally none of this is necessary. It supports my learning only in the sense that it makes me feel like im doing things right. I rarely ever come back and read them (usually only ad-hoc looking for something I knew I wrote but cant remember, not a structured review of them). Your system is for you to figure out yourself. A lot of it came from imitating my math teachers. But maybe the description helped?

Some days I write the date and a margin, and nothing else. No pressure, not every day is a notes day. Some days you learn a ton, and others don't challenge you at all. Thats normal too.

40 years ago we just wrote as much as we could down. The teacher usually hand wrote on the chalkboard. Some courses had slides, a precursor to PowerPoint. There is some reasearch that writing down on paper or with a stylus puts the stuff in extra places in our head.

I never learned to take notes. Good grades but think my notes were always rubbish!