I recently went through a Start Up Weekend event as well as a Venture School program through the University of Iowa. The entire course was on doing exactly what you are asking. They teach the lean start-up and business canvas model of proving a business idea.

The core strategy with proving your business has potential is customer discovery - determining a hypothesis and testing it through interviews (customer discovery). You'll do these interviews with several different hypotheses, concerning every aspect of your business idea - the problem, the potential solution, who are the possible consumers, what will they pay (if they will pay), distribution models, sales tactics, etc. I've provided a few links that present the theory behind the business canvas. It provides a means to be agile in your business development, helping you identify when to pivot or change up your idea to best fit the market needs.
www.slideshare.net/esaife/business-model-canvas-101

https://www.youtube.com/watch?v=QoAOzMTLP5s

https://strategyzer.com/canvas

Good luck! Happy to chat further if you have questions about this concept or how to use it.