what you might be missing is UV-mapping. It is a way of defining how a 2d image is wrapped around a 3d model- so that the 3d model uses those textures. All 3d packages come with an UV editor (i.e 3dsmax, Maya, Blender, Cinema4d, Silo, Modo,...) but Sketchup I believe only has primitive UV tweaking and no real UV editor.…