Making the jump from the solution for my personal pain point to a market-ready idea.

I'll start with my personal pain point. I was scrolling through hundreds of personal ads on reddit to find a very few that met my location, age, and gender preferences.
I have beginner to intermediate programming ability, so I fired up replit.com and wrote a python script that periodically checks the subreddit r4r and emails me when it finds a matching post.
This worked well for me, and saved me a lot of time.
Eventually, I began to wonder if I could build this out as a service and sell it. I've started hacking code together to build a multi-user version. I'm confident I can build it, but not so sure I can build it well - especially the first time.

But maybe I'm getting ahead of myself. Would people even want a service like this? Would they pay for it? How do I broaden my perspective from "I built this and it solves my problem." to "Lots of people have this problem and would be willing to pay for my solution." ?

What resources and research activities are useful to me at this stage? Which things are a waste of time?