I’ve slept more than twice since using SketchUp to any significant extent (and I’m in my 9th decade), but I seem to recall that there are files of objects that one can download. The sad thing is I’ve forgot what they are called or where to find them; so searching is not helping me.
Would some kind soul please kick me in the behind and remind me where to find such?
Perhaps you are thinking of the 3D Warehouse. It hasn’t supported SketchUp 2017 Make for years but you can search the 3D Warehouse in your internet browser, download the Collada version of the the objects, and import the included .dae file into SketchUp.