You have a misunderstanding here. KiCad always displays a mock-up of the board with its pads and the silk screen. If this is all you see then most likely the model does not exist.
In the past there was an error message for every missing model but that confused users into thinking that they had an installation problem. The reason the model path exists in the first place is because we on the official lib want to be able to add a 3d model without needing to touch the footprint. This is done because we are already lacking resources so doubling the work needed for every 3d model contribution is really not possible.
For adding 3d models see Tutorial: How to make a footprint in KiCad 5.1.x? - #5 by Rene_Poschl (section 3D-Model handling and possibly more interesting section Adding the 3d model to the footprint)