The tips begin at a different place in each module. The advice moves along with the stages of the course.
Science passages are constructed by AAMC, not selected from the work of a third party. The author of a CARS passage really is trying their best to communicate, but the same is not true for the author of a science passage. Everything in a science passage is intended as a challenge to intelligibility. Sometimes the intention is to set up a question, sometimes to stress your working memory, attention, or ability to recall a knowledge item. Study the passages in the section bank, not just missed questions. Imagine you worked at AAMC. There's an art to what they do. Learn to laugh when a passage is brutal. You can become immune to it.