I am a 1L who just finished first semester so keep that in mind, but I did do very well so maybe I can help. As I'm sure you already know it's super important to go to class. Even more important is to take care of yourself and get plenty of sleep and exercise. Staying up all night can lead to a point of diminishing returns where you aren't retaining that much and actually hurt yourself by being more tired the next day and so on.

Beyond that, I never wrote a single brief on paper all semester. I did everything in the book with a black pen and a highlighter. I would often see classmates using like six different colored pens and highlighters but to me that just looks like a pain in the ass. I read the cases very closely, wrote a brief fact summary at the top of each one in case I got cold called, and then from there on out focused exclusively on the rules applied in the cases and how they compared to other cases we'd read, especially the other cases for the same reading assignment. By the time I got to class I really felt like I knew how the discussion was going to go. That is not to say I knew everything (that's why going to class is important) but with a few notable exceptions I was able to get through most classes taking only about a page or so of notes.

When it came time for exams I snagged a few outlines from previous years in the class and went to work kind of customizing them and making them my own. As I went through them I reviewed the individual sections in my notes, in the casebook, and in a supplement. (E&E for torts, Chemerinsky for Con) I took about three practice exams for each class. That was it. I think things like multiple choice questions throughout the semester are more useful than constant practice tests, especially when you don't know all of the material yet. Also, talk to your professors if you're struggling with a concept, I guarantee you aren't the only one. Hope this helps, good luck!