I'm a trainer
If you don't have organizational skills, discipline, patience, courage, looks, charisma, charm and social skills, training isn't for you. However..if you do have those skills listed above getting clients is as difficult as you make it.
If you put in the effort to do things for yourself and your business (of training) you will do well. If you depend on handouts from your fitness coordinator or do nothing to talk to people outside of the gym, you won't make enough to survive.
Training shouldn't be your primary job. You should have another job or plan on moving up the ladder to director or even owner.
and finally make sure your good, if you build a reputation for yourself it will make or break you.