Let us go through the installation of Rhino and your IDE - Visual Studio 2017.

You can see the official explanation here:

http://developer.rhino3d.com/guides/cpp/installing-tools-windows/

This is the link for downloading and installing Rhino 5 SDK:

https://www.rhino3d.com/download/rhino-sdk/5.0/release

This is the link for downloading and installing Rhino 6 SDK:

https://www.rhino3d.com/download/rhino-sdk/beta