Hey welcome aboard,
I particularly had a lot of trouble with memorizing stuff, so most of my notes were pointing out of were things I needed to memorize were so I didn’t loose time searching for it (googling it wasn’t a thing yet), or some condensed version of it (if I managed to condense the information in a way that made sense to me).
I have a very logical and analytical mind so sciences and math was way easier for me to understand and comprehend and I found early that understanding thing really made it easier to me so I had less things to memorize so I kind of “cheated” my brain over trying to understand the topic instead of trying to memorize everything.
Also whatever system you use, always try to fit it and tailor it to your needs and how you think not the other way around, it can take some time to find and figure out what it works for you and what wont, but eventually you will get something that makes senses and you can understand and work with.
I’m not sure what topic it is,but try to figure out the central point of the thing you are trying to take notes (it can be hard to figure it out sometimes), and get a very base version of that that you can understand (or link to more detailed explanation of it if you need to) then expand from that to put other things that you think might me relevant or that your teacher said you should pay attention too, a simple example of the thing (if it’s appropriate) can help your brain remember better what is about, some people get good with making analogies with the topics so they manage to simplify it somehow, also some people have a better time drawing things instead of writing things can be helpful, it can be a bit of a trial and error in the begging but eventually you get something that works for you.