You will need to talk to zoning, animal control and get a special use permit. They will come out an inspect your kennels if you are allowed to open a business. You will need a business license.
There is a lot of red tape to cut through and a lot of requirements you must meet. I groomed dogs in my home for 5 years and was all of a sudden told I could not operate my business cause of the zoning restrictions.
It may not be worth the effort if this is to become your major source of income. Just keep in mind that you will be training the owners to train their dogs. And, in my experience, the people will not follow through on their own because they think you don’t know what you are doing and will alter what you have taught them. It was the owners I had problems with.
I trained dogs for several years and the owners just don’t get it. I specialized in aggression training and it never failed to amaze me with the mentality of the owners. They screwed up the training and then blamed me.
It depends on what kind of training you plan on doing. Obediance? Well do you plan on having classes? You can lease a place but you need the proper zoning to hold dogs – local courthouse. If it’s one on one you can set up a website talk to the local vets for referals in your favor and drive to the people’s home.
If you need a loan then you need to put together a business plan in order to ask for money. SBA.gov is a good place for that.
Good Luck