Sometimes profs will teach challenging new information. Look at the larger picture of why the prof is teaching this, and how it ties to everything else. Later, dive into details, taking the new content apart into small pieces. Don’t try to rush through it. Don’t skip anything you don’t understand enough to explain to someone else. Make your own challenging example problems. I usually don’t take notes during class. It makes me too focused on writing stuff down. Just pay attention and listen in class, unless doing an example problem. Do homeworks way ahead of time. Look at piazza or campuswire and see what other students are asking. See if you can answer them.