How can I turn my business into a franchise?
It sounds like you haven't actually started your first business yet. You will need to start the business first and then run a number of vending machines for a while so you can get the business figured out from a marketing and operational standpoint.
You'll need to develop all of your sources for machines, supplies and your inventory of coffees and teas. Then you'll need to make sure the business can operate profitably for a period of time so you can demonstrate that success in some form or fashion to prospective franchisees.
Even at this point in time, you'll then have to determine if franchising the business makes economic sense. There are many costs involved in starting a franchise company and the total investment to reach breakeven in a franchise company operation for any concept can easily reach over a million dollars.
It may be wiser for you to expand the business in another manner other than a franchise. You can receive expert advice once you get to this point in your business from a good franchise attorney--they will help you make sense of your options.