Any words of advise on how to pursue a career in diet and fitness?

I would like to learn how to become an expert in fitness and diet. Any advise on the different career paths and how to get there? I think it would be great to help people achieve their fitness goals and get healthy. ThanksAny words of advise on how to pursue a career in diet and fitness?Don't just learn the science, but also learn how the Constitution was designed to protect your right to provide education to others.