It all depends; I didn't do well on the first few tests involving electron pushing mechanisms and stereochemistry, but came time to synthesis and Grignard reagents, I did really well because by then I knew the basics and the topics were applications of the basics. The topics that you probably need to be prioritize when you take Orgo are:
First semester
-Nomenclature
-Stereochemistry
-Sn1/Sn2
-Mechanisms!
-Intro synthesis (Grignard, alkenes, alcohols)
-Spectra (IR, MS, H1 HMR, and maybe C13 NMR)
Second Semester
-Aromatics (know this well! There are many concepts that seem tricky, but are actually pretty basic; the trick is to not get overwhelmed)
-Ketones
-Amines
-Carboyxlic Acids (You better get to learn this functional group well)
-Alpha substitions, condensations, enols, and enolates
The order of the topics you go over range from school to school, but this seems standard for several places. Depending on how fast your class proceeds, you may cover biochemistry second semester, involving carbohydrates, amino acids, and lipids, but usually the professors test general knowledge more than specifics.
Hope this helps. I took orgo last year, and it took me a while to get the hang of it. Ironic thing is that I really like organic chemistry now, compared to biology and physics.