Hi @smcb3357 ,
Check this plugin for an easy solution: PlaceMaker
Continue below to do it manually.
Use SketchUp Pro’s terrain feature.
1- You can check Open Street Map (OSM). If you’re lucky enough, somebody already drew your buildings with appropriate height and roof types etc. , so you can just export your desired area which will download an .osm file. (If not, you can spend some time to edit/draw it yourself via online tools they provide. Note that all the editing/creating you’ve done will be public when you save! Also there is JOSM in order to create more advanced structures and option to only save in your computer)
2- You can convert that .osm file into an .obj file via this: Osm2World, then you’ll be able to import that .obj file into SketchUp (use meter as unit) which includes 3D mesh (hopefully without a problem). (You can check OSMbuildings.org in order to preview the available 3D data.)
3- Use this plugin to drop 3D structures: DropGC on to your terrain. You might need to close bottom gap in order plugin to work. Then refine/adjust 3D structures placement via ‘stamp tool’ (You can do this all at once but one by one might result better).
Note 1: You can also import .osm file directly with this plugin: OSM Path Importer. This imports 2D lines defining roads & building borders etc. You can then use ‘drape tool’ to the terrain you grabbed.
Note 2: CleanUp³ tool might come in handy in the process.