I last went to a lecture during covid, and obtained my last advanced degree over 10 years ago so the rules may gave changed. Back when I took core courses, the teachers used blackboard and chalk and whiteboards were just coming in.
Assuming teachers are using white-boards or blackboards, note taking is relatively easy. When a teacher / professor writes an equation on the blackboard, or makes a diagram on the blackboard, you reproduce it in your notebook. That is taking notes.
You say you can get notes from friends. Try this. Take notes by putting your teachers exposition on the blackboard in your notebook as I have said. Then borrow notes from your friends on the same day as your notetaking. I am ninety percent sure, your notes will almost exactly match your friends notes in content, except for handwriting differences. (Unless you are dyslectic or have some other difficulty.)
Go to and take notes like this in all classes, any you will be a good notetaker, like your friends. Why not?
I tend to put the date and lecture number on each page and begin each lecture on a fresh page and keep all the notes in one place, (a folder or a notebook). If I am as ambitious as I should be (but almost never do), I add to the notes taken every day with my own notes when reviewing the professor's lecture notes.
One intersting story I remember about taking notes in a lecture. One day the professor put a strange symbol at the end of the equation which I did not recognize at all. I reproduced the weird symbol exactly as I saw it and he had written it, in my notebook. I meant to ask him about it later.
I reviewed the notes the next day and although the symbol was no different from what he wrote on the blackboard, I recognized the symbol. (I do not recall what the symbol was, it may even have been a punctuation mark at the end of a sentence, or something like that). If that happens to you the best advice I can give is reproduce the symbol in your notebook as best you can, for when you can examine or refer to it later