hi ! i’m actually starting creating a gam, but i have a little problem: some 3d models are very interesting, and i want to use it in my game. but i wan’t to know if using models is legal ( copyright etc . . . ), and i wan’t to know if i can sell my ggame, using some 3d models of the warehouse.
thanks 
You should read and have your lawyer look at the terms of service for the 3D Warehouse to determine exactly what you can and cannot do just to be on the safe side.
You also need to be using SketchUp Pro as you can’t use Make for commercial purposes such as you have in mind.