Organic chemistry is a very vigorous field and much has already been discovered about organic compounds and their reactions. Many organic text books are now about 1400 pages long. You cannot expect to learn all this material without investing considerable time and effort in studying. The pace of the course is brisk and allowing yourself to fall behind in your studying will spell doom for most students. First, organic chemists are interested in the structure of organic molecules.
Organic chemists are also very interested in the three dimensional shapes of molecules.
The branch of organic chemistry that deals with three dimensional shape is called stereochemistry and will be a very important part of the course. Second, organic chemists are very interested in chemical reactions. In learning these reactions, you will want to know what products will be obtained if two compounds are mixed under a given set of conditions and also what kinds of reagents can be used to cause certain types of reactions to occur. Third, for many reactions we will study, the details of how the reactions occur are known. When a reaction occurs one must first know what reagents were used as starting materials and what the final products are.