Hi anneanne,
V-Ray is fully compatible with SketchUp 2017 Make (Pro license is not required).
The .vismat material type is very old and has been deprecated.
The standard file extension that we use now is .vrmat (since 2013 or even earlier ).
I’d recommend you use the materials from the built-in material library - I can see you’ve downloaded it already on the screenshot.
Where do you want to import objects from?
Every object that you add to your SketchUp model will be rendered by V-Ray without any additional actions required.
Regards,
Konstantin