The answer Paul gave you is a very good one. This industry is a great one to be in, but it requires a lot of dedication and time spent in keep educating yourself if you want to be a top trainer. We all started form the bottom at one point and climb up form there. But, if you are going to be in this for the long haul then you will need to be involved with as many aspects of this business as possible. It’s a slow process, but if you do it correctly then you will be a successful one.
This question comes up in this forum every few days. Below I have a link to a similar question to yours that was asked a few days back. There have been many great questions and answers though out the years, so if you have time to go over as many as you can you will find a lot of useful information. There is no right or wrong way to go about this but keep in mind that there is a lot of competition out there, so being as much as informed as you can it will play to your benefit.
And as Paul mentioned, you will get many great answers here. I wish you good luck!