In the field of training it's hard to market based on credentials or qualifications, since there really aren't any that are recognized or understood by most customers. It's also difficult to target the right decision-makers who might retain you for training offerings, or launch paid marketing campaigns since there are few advertising venues that are affordable and target those buyers.
When you start a training business much of your business is going to come through contacts you've made in the training and human resources community in your local area, at least initially. If you have not made contacts in the years prior to hanging out your own training business shingle, you are probably going to struggle.
This is a hardship for those who don't have any experience, contacts or track record prior to opening a training business, or for those who, during their training careers as someone else's employee, have not developed a network into the marketplace.
What that means is that the time to think about creating a contact network to access training purchasers and decision-makers is while you are currently employed, and not when you open your business. We're taking about getting to know people, and getting known, and NOT sales.
So if you plan to ever open your own training business spend time getting to know potential clients, socializing, making a name for yourself, and remember that regardless of whether you are currently employed by someone else, or are self-employed, that EVERYTHING you do now and in the future will have an impact on your marketability, and hireability.