The leading slash in "notebook_path" probably won't work on Windows. It makes it an absolute path and so Windows throws a drive letter in there for you. Z:
You could use a complete path like "C:/Users/YOURLOGINNAMEHERE/arcgis/home/" or it could be relative to the current folder if you leave the leading slash off like just "arcgis/home" if your data is in the local folder.
I use tests a lot like
import os
if not os.path.exists(notebook_folder): print("THE PATH DOES NOT EXIST!!")