The most obvious answer is: you need to have been trained in Management Training first before you can hope to put up your own Management Training business. And that may mean getting higher education, perhaps earn your degree in Management or Business Management first, then getting a job in a company which deals in Management Training so that you learn how the business works without putting any of your finances at risk.
As in any field, it always helps to have mentors. Your personal mentor maybe your professor or instructor in university, who will tell you what Management Training areas to get into or not get into (and why.) Your superior in the Management Training company could also be a mentor (if he is willing to pass on what he knows to you.) Even colleagues who have been working in the Management Training company longer than you might be eager to show you the ropes they too can be mentors. Nurture relationships with these mentors because their insights (earned over time through their own experiences) may be valuable to you as you consider getting into business in Management Training yourself.
One Management Training company that you could eventually choose to put up could be a Management Training Simulations company meaning, a company that will put employees under training in various Management Training simulation scenarios so that the employees will realize that the Management concepts they are being taught do apply in real-world situations.
Another Management Training company that is good to get into is a Business Mediation company. Business mediation is, like the term implies, the function of getting business competitors to sit down to negotiate so that they can come to an agreement. You cannot send an inexperienced manager in to a crucial series of negotiations unless he has been trained in what to expect so that is where the value of Management Training comes in.