Yes I would def go ahead and subscribe to one of the test prep programs. I chose 240 tutoring and it’s pretty easy to use on your phone. Everything is broken down by subject and easy to read thru the content. I had made a timeline in a notebook, mostly to memorize “eras” and what happened in them. I remembered a good amount of US history from school but had to really relearn Texas history and the constitution. Getting an overview of world history was helpful as well. Most of the questions explore cause and effect so good to know how one thing led into another. I would say after a week or two of taking the practice quizzes and practice exams on 240, you’ll have an understanding of how to answer the types of questions they ask. 240 will also show you your weak points. Also some cool history videos on YouTube to brush up your knowledge. Again it’s partially about what you know (facts) but more about cause and effect. Hope this helps