Becoming a personal trainer takes some effort, but it can be a very rewarding career.
There is a lot of turn-over in our industry and it can be competitive. Here are some things about personal training that you might want to consider.
1) It’s not just about the hour you spend training the client. You will (or you should) spend time outside of that session planning for that client.
2) It’s not just about your ability to teach others what you know about your body. You need to learn about all sorts of types of bodies, health conditions, modifications, etc. As a fitness enthusiast, you’re already an expert on your own body, which is a good start. But you need a personal trainer certification that will teach you how to work with the public.
3) You need to have selling skills, unless you work for a club that gives you clients.
4) Education is important. But so is experience. You might want to do some informational interviews with trainers in your area to see what their day / week / job is like. You might also shadow them training for a few hours if they allow.
I just answered a similar question but most of it applies here so I am pasting the body of it for you.
Any NCCA accredited personal training certification will get you rolling. What I recommend is about what you should do after passing your cert exam. Learn about everything that interests you. Learn about things that your clients need to help them. Learn, learn, and learn some more. As a personal trainer or any type of fitness professional you should consider your education to be the most important thing about what you do. We are in some of the most exciting times for the fitness industry. Research is constantly updating information and techniques for training. A lot of fitness pros go with what is popular. This may be financially beneficial, but it can lead to poor outcomes for the clients. If you go with something trendy, I hope you exam the movements and potential risks closely. A lot of people have been seriously hurt doing extreme fitness because they weren’t ready for the motion, the weight, or a number of other things that should have been worked on first.
So learn how to get a person fit and healthy then learn how to progress them if that is what they want to do. Good Luck!