Vuforia core samples not importing at all!

I'm trying to download and import the Vuforia Core Samples but I'm having no luck whatsoever.
I've gone to the assets store in the unity editor, downloaded and imported the Vuforia Core Samples project, but only the common folder is downloading and I'm not allowed to select any of the other project folders. Lastly I keep getting this error message whenever I try to save and restart the program:

"Assets/Common/Scripts/CameraSettings.cs(11,7): error CS0246: The type or namespace name `Vuforia' could not be found. Are you missing an assembly reference?"

I'm completely new to unity as well and that doesn't help at all.

 

I think you can import it again, or delete the vuforia folder, and recreate the ARCamera to re-import the vuforia folder