Taking good notes is a skill that takes work to develop.
Good note taking starts with reading the material before class and taking some notes from the reading.
Pay attention in class. The instructor will give you clues as to what is most important.
This can be anything from saying, “this is important” to talking slower to a change in voice tone.
Leave a lot of “white space” in your notes (you should not use more than about half of the area of the paper) so you can go back later to fill in details you did not get written down during the lecture.
If you don’t know where to start on note taking, talk to your instructor.
The time you spend learning to take notes will help for years to come.