Use the emphasis given in lecture as a guide to the relative importance of the different topics covered. If a subject is glossed over or skipped completely, do not worry about it. In fact, you are told in the course outline to skip certain sections of the book. Take advantage of the free tutorial sessions to get your questions answered. Get your own tutor early on if you know that you will need extra help.
Tutors are often hard to find later on in the semester.
Learning organic chemistry takes a lot of hard work and hours of studying. There are no magic formulae or simple solutions. Don't wait until the last night before an exam to start studying. You are guaranteed to do poorly under those conditions. Take advantage of the help sessions before each exam to get your final questions answered.