At CSN you will be eligible to take the CNA exam once you are pass the Fundamentals of Nursing class with a C or better. The process is simple fill out the application, which I have attached a link to, get finger printed, then wait for a letter in the mail stating you can register for the test.
Taking the CNA class is a waste of your time, because those topics are covered in Fundamentals of Nursing and none of them are difficult to grasp.
The real question you should ask your self is, "do I have the time to learn a new skill while in nursing school"? It may be a CNA position, but there is a lot more to it than meets the eye and it requires time to learn. Nursing school is difficult. You have a lot of material you are going to cover and not a lot of time to learn it.
All that said, I do not recommend becoming a CNA during nursing school. My advice is that you dedicate 100% of yourself to school while you are in the program. Study, study, study and be the best student nurse you can be, because your future patients deserve that of you.