How many credits should I take my freshmen year in college?
Depends if you are on Quarter or Semester? 45 units/year for Quarter and 30 units/year for Semester are around the average. Much will depend upon the types of classes, if they have labs included and the type of student you are in terms of previous HS rigor, study habits etc…
The school I’m currently attending is on a quarter system, but they are going to transition to a semester system in fall of 2016. I am taking one class with a lab as of now, and I am taking 12 credits. In high school, I took 5 AP tests and all AP/Honors courses except for 2. If I’m trying to transfer to USC, should I take 15 or more?
It depends upon when you plan to transfer and how many classes are needed for the transfer. 15 units is average, so if you can handle more, then go ahead. You should have a list of transferable classes so take them based on your intended transfer schedule.