Divide map into areas and attach data to them

Hello fellows!

I am really new to Unity and all game development, have basic knowledge of .NET only.
I downloaded 3D map to Unity of streets and building, what I want is when you select a part of street, I would like to see some data. By now I am trying to figure out how to divide the map into areas and how to attach data to them.
This is a part of hololens project.

I would be glad for any advices or links to tutorials.

Best,
Alex