On the " Your First Python Script in Rhino (Mac)" page:
There should be no slash between “Application” and “Support”
~/Library/Application Support/McNeel/Rhinoceros/Scripts/samples
Editing a Python Script
You can open any of the sample Python scripts in a text editor. From Finder navigate to the samples directory:
/Users/HOME/Library/Application Support/McNeel/Rhinoceros/Scripts/samples
(replace HOME with your home directory name).
Or in the Finder, use the Go pulldown > Go To Folder… and type:
~/Library/Application Support/McNeel/Rhinoceros/Scripts/samples
And there is nothing in the “/Scripts” folder