22 is a bit old to start if you plan to be a world champion, but you should still be able to have a significant competitive career.
If competing is your real goal though, you may want to think about getting out of the teacher training program and moving to a studio that trains amateur competitors who compete together in partnerships (or more specifically, finding a specific teacher with a history of training amateur couples to competitive success). The reason is that as an amateur you will have far more opportunities to compete against peers at each level of development - you can start competing with only months of total dance experience dancing against others of similarly limited training, and then just keep moving up levels as you build skill and experience through the highest amateur division where you will first go up against those who danced as children. If you then decide to turn pro, you will hit the ground running, prepared to be not just a professional teacher but a professional competitor.
In contrast, if you stick with the teacher training path, most of your time will be concerned with what marginally interested social students need to know - lots of fluff, very little substance or depth. And that's the part of your training that is even about dancing, rather than about sales. You may face restrictions on who you can have as a professional partner (they may have to work for your studio or an allied one). As a junior professional you will have fewer competitive alternatives than as an amateur - the chains do have internal divisions for low level pros, but mostly you would get your initial experience doing pro/am comps with low level students. In contrast to a ladder of 6 or so divisions to climb in the amateur ranks, there are really only 2 pro divisions, and they have about 80% overlap of people - in other words, while the lower division wouldn't have you competing against the national champions, you would be competing against people who are competing against them.
The amateur divisions also offer additional age categories for those over 35, 45, or 55, while most professionals retire from competition to refocus on teaching, judging, or raising a family by their mid thirties.
If you do stick with the teacher training program, you are likely to have better prospects in the professional american style divisions than the international ones - fewer of the overseas trained former amateurs who dominate the professional international style competitions take interest in american style, while the studio system has more of a tradition of pursuing it. People with a diverse dance background before ballroom may also find their previous experience more directly transferable to american style than to the more uniquely ballroom techniques stressed in international style.
