I don't really know how to use Khan Academy for studying SAT. As I skimmed through it, I only saw some explanation and one or two example questions. Are there any suggestions? which website or resources to use?

Its my first time to take SAT test and currently I finished SAT Prep Test for R&W, only got 38/66. I asked claude and Chat GPT for the score and they've both said its between 530~550. Is this a capable score for my first test or weak. My weaknesses were transitions.