If you want to use CUDA rendering in Rhino 7 with Rhino Render or using Raytraced in the viewport then you as a user don’t need to install anything to have that enabled other than ensuring you have the latest NVidia GPU driver for it installed.
With that done in Rhino 7 go to Tools > Options > Cycles and check the render device section. Make sure the CUDA tab is active and that you have your GPU selected in there. Cards from GTX 9xx series and newer should be supported.
Yes, Rhino already used my GPU when I move/rotate/copy/… object.
However, I also noted that when i change viewport mode from wireframe to shaded, it seem like Rhino does not use my GPU, but it used my CPU instead.