I would suggest reading the book 'Predictable Revenue' https://www.amazon.com/Predictable-Revenue-Business-Practice... . It will help in defining your marketing segments and how to reach them.

When I first started my saas, I incorrectly didn't start by gunning for paying customers. You could make a cool product, but your goal is to make a cool product people will actually pay for.

The second lesson I learned was not charging enough, but once you actually get people in your paywall, those are things to refine later.