Ask HN: How to research an app idea when you have no idea of where to begin?

I had an app idea, but while starting to research, I found myself staring at Google search bar. I had no idea where to begin, what to search for, and Google results to whatever I was searching for were not satisfactory.

What are you trying to research? If you have the idea already, are you trying to find out if it exists already? Are you trying to find potential customers? This is very vague.