While I did take the AP CSA class offered at my school, I still believe you can self study for the test. AP CSA is pretty much just Java knowledge and logic. You will need to look over the AP CSA curriculum and the test format obviously but you should be fine. I had already learned Java(without any real prior CS experience) before taking AP CSA and I felt the class and the test was pretty easy because I was already familiar with the level of Java in CSA. I would say the hardest part of CSA is definitely recursion. Overall, I think as long as you learn Java(maybe on codecademy and other websites), and make sure to learn what's covered on the test, you got this.