Simply asking “how to find the right audience” reverses the question. First, you find the problem and the audience, and then you build the MVP to serve them.
See, identifying the right audience for an MVP begins long before testing. It’s the first step in building an MVP, where you conduct market research and brainstorm ideas. Between competitive analysis and user research (e.g., customer interviews, surveys, and focus groups), you will build your MVP around what your specific audience wants.