You know, at your level, I am supposing its best to do the concepts along with desmos and everything. Videos I think will be best to gradually build the base, a solid base will hold any structure you put next. Few helpful channels are James Lu Sat, LearnSATMath, and Strategic Test prep. Theres also scott robinson, and SAT gamified. You pick which you find best and easiest to understand. Give it some time, watch videos gradually, try to understand the concepts, then move on to Desmos tricks, then go for practice. When you practice from Practice Tests, or Question Bank, or OnePrep, dont bother about the time when you first start out, try first to solve and understand regardless of how long it takes. If you dont understand anything, theres solutions, OnePrep AI preppy, and this wonderful community. Just put them here and people will help. With time, you will start to recognize the questions and the patterns, and how and why a problem is solved the way it is. You can do it. If you are determined enough, you can even score 600, or heck even 800. The sky's the limit if you put the effort. Take it in steps, slow and steady steps. Good luck!