How to make something of my hobby

Hi there just have Question please ? (Fine to share on Facebook)

Few years ago I started a hobby as a "like page" on FB (free advertising for local businesses and events in our town)
since then it has grown in members and popularity, I love doing it! Many people would give up on it and abandone a page like this (as a lot of those swap and sell type pages do)

I know it could be something bigger ... Something that could potentially make money etc although it is just through FB at the moment.
I just don't know how ?, I don't know where to even start!?
Maybe it could be a website or an app ... But even with that who do I even ask?
And all The legal stuff scares me! I wouldn't want to accidentally break the law some how and get I trouble.

Agh I try to be positive but then I think it's probably just going to be an idea that I never went through with because "i didn't know how"
Story of my life lol ?
If anybody possibly any positive ideas or answers I'd be hugely appreciative!!!
Thanks so much! ?