My advice would be to look over sample questions/tests online and review the questions you got wrong. I would make sure you try to study 3-4 hours a day, if you are still in school or 4-5 hours if you are not. It is important to study everyday because that way you will be able to retain the information and it becomes easier for you to study the rest of the days. As Stephanie mentioned, Quizlet is a great resource you can use to study. You can create multiple flashcards and study them until you are confident. This is not said enough, but do not take advantage of the questions that you think are "easy." Make sure you study those questions as well because that question can pop up in a test and you may forget it if you neglected it. On the night before your test, make sure to review. Lastly, It is important to receive a good amount of sleep and to eat and drink regularly during the times you are not studying. Even going out for an hour or two is significant for stress levels.
I hope this post was helpful, good luck!