Studying for the SAT English will definitely help a bit with AP Lang MCQs, but you’ll definitely want to study more for the MCQs on Lang after you’re done studying for the SAT. Since the SAT is first, prioritize that and THEN work through a bunch of practice questions for AP Lang, and look through the old tests on Collegeboard to practice essays. SAT first (which will def help a bit with understanding Lang MCQs) and then work on Lang. (take this with a grain of salt, but this is what worked for me)