If you got less than a 3.0 on Anatomy, Physiology, Nutrition or Lifespan psych, then you should absolutely retake them. You will need a lot of the knowledge in nursing school, and would be good to continue to develop and find study techniques that work for you (with challenging material) before you start in a nursing program. Especially if you want to go on to advanced practice, you need a good foundation and can't let excitement and impatience get in the way of really learning what you are in school for. Don't give up your dream, but you might need to relax on your timeline. You should definitely volunteer in the type of healthcare setting you want to work in as well. Like the others said, it really depends on the schools in your area on if that would be enough. The ADN program I am in is highly competitive and I also needed to go work as a CNA first to get in (I had a 3.5 and volunteer hrs). There is nothing wrong with a noncompetitive waitlist if there is one in your area, but I would spend that time just waiting, I would be preparing myself to succeed when I got in.