You could seed the map by scraping things like local papers, historical archives, reviews of all kinds, etc. maybe giving them a less prominent appearance compared to user submitted. Getting people using and exploring the tool right away instead of being met with walls of copy and detached forums might be a good move. You could pull the old reddit move and spend a few days adding a tonne of your own stories under different names and/or try and find some others that would be interested in doing the same. Others here would probably tell you to just use LLMs, but I'd avoid that.
As it stands I think you will have a hard time getting people to start filling your database.
As it stands I think you will have a hard time getting people to start filling your database.