Hi,
I have a master’s degree in sport administration and I'm also CSCS certified. The difference between the BS and the MS in exercise physiology is that in the BS you are learning the basics of everything, from science, sports, fitness, and everything is very general. In the MS it gets more specific to ex. phys., and depending on what you are interested, you focus your time on researching a specific topic you want within ex. phys.
The BS will definitely help you with the CSCS but you also need to know about sports training, testing and program design. The CSCS is specific to sports training, while also knowing about exercise physiology, anatomy, biomechanics and nutrition.
After you learn the basics, if you want a career as a CSCS, the best you can do is contact the college department of strength and conditioning and talk to the coaches about your interest in the field and tell them that you want to learn. In strength and conditioning networking is a big thing and the sooner you start the better.
Welcome to the field, to learn something new everyday just keep your eyes and your mind open.
take care