I don’t think MCAT is worth studying for so early unless you’ve taken courses in the subject matter at college or the AP equivalents (in some cases). These would be all of gen chem, all of organic chemistry, intro biology/physio, physics (mechanics, electricity, and fluids/dynamics), intro psych, and intro sociology. You could self-study the content beforehand if you wanted to but I don’t think it’s an efficient use of time. Either way no harm in getting a couple of books to brush up on content if you want to. Commonly recommended brands are examcrackers, the berkley review, kaplan, and princeton review.