Organic is difficult. If you are at the stage of taking a final exam, cramming with compounds and functional groups now is unlikely to do you much good. There are definitely some that you need to know; try to put them into categories that make sense to you. Otherwise, understanding the underlying principles will get you a lot further, especially if you are getting ready to take an exam. I've attached a couple of links that break it down into the basic, big ideas that you need to know in order to get through the course. I see you are in high school, so the level you will need should be reachable by doing this.