Are you asking about the MCAT? Everything you need to know for the MCAT was taught in your freshmen science classes. You just need to think out of the box while applying said knowledge to the MCAT questions.
I studied for probably 3 weeks on General Chemistry, Organic Chemistry, Physics 1 & 2, and Biology 1 & 2. I scored a 32, which is a fairly decent score, as long as your GPA is decent as well.