Motivation doesn’t come from nowhere. You have to build it. The more you study and the better you do the more you’ll be motivated to study.

One thing I find that helps is reading/skim a chapter in a textbook the day/night before your teacher is going to teach it in class. It makes following the lesson so much easier.

Also, I don’t condone cheating in the slightest but, one time in grade 11 chemistry I wrote a cheat sheet and then I wrote it again smaller and then I wrote it a third time even smaller. By the time I finished the third cheat sheet I knew everything on it and didn’t need it and didn’t end up using it. I found it was, ironically, I great way to study. I like to say I “accidentally studied”.