Would I be better off getting certfied through ACE or studying exercise science at a local community college?

I am interested in helping out other people to be healthier and more active, especially with good nutrition and psychical activity. However, I have been taking a couple of fitness classes at the YMCA along with my regular running and swimming activity routine, and I was recommended that if I cannot study exercise science and nutrition at a local community college, that I could still be certified by the American Council of Exercise and get CPR certified. I have never had a job, except for volunteering, and I just want to know what would be better, as well as money wise. If I went through the at home study program, and then took the certification exam, it is less expensive and valid for a couple of years.