The difficulty of Orgo is way overhyped. It really is just a way of thinking. I like to think of it as little 5-10 minute puzzles that you need to solve. It's pretty much understanding how electrons will move. The best way to master the material is just to constantly do practice problems. If you don't understand a lecture, watch the khan academy video at 2x speed; this helps immensely. Also, as you learn, any time you come across a new mechanism make a little note card of the mechanism. Do not memorize the mechanism, just understand the relative patterns that emerge. For example, when you see an alkene, understand that many times the first step will be to protonate the double bond to convert the alkene to an alkane. Also understand which mechanisms are markovnikov vs. anti-markovnikov, and which are syn additions vs anti additions.
For me, I had the most amount of trouble with initially understanding when the SN2 vs. SN1 vs. E1 vs. E2 would take place. I was able to get every question right on the test for this part by just drilling practice problems. I did every problem in the book, and even googled additional problems and solutions to help solidify the material.
Lastly, the first test is likely the easiest (material wise), or at least it was for me. This is because by the first test, we had only learned 1 mechanism and newman projections. Unfortunately, I did not take advantage of this, and just didn't study much at all. This resulted in me getting a C- on the test, and getting a B+ in Orgo 1. So study and do problems, even when you think you understand a topic entirely.
EDIT: Read the book and take notes from the readings before each lecture. This shouldn't take too long (like 30-45 minutes), but really helps.
