What are tips for the Critical reading part and what vocab flash cards should i use?

hey i am a sopre in high school. In the PSAT i bombed the critical reading. could someone please give me some tips and also please tell me what SAT vocab cards i should use to memorize because i had bought a Kaplan one with 200 of vocab words, math, and writing tips. but, the words were too easy and not in any of my practice PSATs