Taking pre-calc over the summer and have not taken a math class since high school, what basics should I learn?

So I’m taking a 6week pre-calc class over the summer and calc 1 over the fall. I haven’t taken math since geometry 7 years ago in high school. I have been watching professor leonards precalculus playlist over the last month and have grinded my way to arithmetic sequences vid.70 at the moment. My goal is to get a small grasp on all the topics that will be covered before I start my pre calc class so when I start it’ll be familiar and I can learn it properly. Although I find a lot of the topics more understandable than I thought I would, I obviously find myself lacking basic rules/fundamentals that if I learn properly I think would make this process a whole lot easier. So what are key algebra basics/rules that I should learn in addition to finishing these pre calc lessons? Thank you very much.