I was looking at a tutorial on how to make a plane and use a modifier to extrude different size blocks and even streets spaces to use as a city, but I did not save that tutorial and now I can not find that instruction. Does anyone know of this? I believe it was a plane sub-divided into squares and I would select the squares into city blocks…Please help!
This tut from Gleb Alexandrov is really clever it’s a little bit more involved than just sub dividing the plan and extruding but it looks nice and is not that hard to do to get the basics in place when I had a go at it.
Could you tell me step by step how to get OSM file into Blender, I do not see an add-on in prefereance with OSM extension?
Follow the link in the tut that says add on 
it links to here https://github.com/vvoovv/blender-geo/wiki/Import-OpenStreetMap-(.osm) standard blender install for an add on the instructions are on that site as well for how to do it, good luck!