I've done research on tools that can allow me to perform market research (google trends, keyword planner, etc.) but I'm stuck on how to be effective with them. I can look up topics all day and get average search results for a specific topic, but I don't know if what I'm looking at is an opportunity or not. I can try to analyze graphs of popularity for a category, but finding how that impacts my idea is difficult as well.

I want to create a product around a market underrepresentation, an opportunity, instead of thinking up a topic and researching if the market even wants it. This is the common problem I run into when researching how to use these tools, everyone assumes you have a product in mind and can research the niches it fits into, but what about the other way around? If you want to research underrepresented markets first then create based on your findings? How do you go about that?

These are very amateur questions, but I do appreciate any help given. Thanks!