I am in the same boat. I go to Nursing school in Denver and the grading scale here is a 78% or better. I was trying notecards and that didn't help. Then it clicked, these are NOT pre-req classes....
I have been a CNA for about 6 years, Nursing student now, but you will only need your certificate. Alot of places like the hospitals will want some sort of experiance and be sure that you have a BLS...