In order to pass the exam you need to master the essentials. Every subject has some fundamental concepts that have to be understood. Be sure to go through a) textbook & lecture notes b) past exams (a must!) and try to find the most important concepts. Start out by learning these, there’s no point in trying to understand the advanced topics if you haven’t mastered the basics.

Once you’ve done this you’re ready to move on to more advanced materials. If you only wish to pass the exam, I’d recommend you to try to memorize the easier ones and leaving the complicated ones. If your intention (as it perhaps should be…) is to receive a higher grade then be sure to go through the complicated ones as well, posing any questions you may to the teacher. I’d recommend collecting all the questions on a piece of paper so you won’t need to look for the teacher every time something new comes up.