Organization and memorization

I will be a senior in high school. Through high school I had a very hard time keeping things organized and memorizing certain topics in class. One advanced class I will be taking this year is health science, this class is my focus program, but that is one my classes that I have a difficult time with memorization and staying organized. Any advice, or tips?

I use Quizlet for vocabulary and sticky notes (yes, instead of a planner) for homework.