How to use Jupyter Notebook with iCloud storage to read a data set?
If you haven't already, first setup iCloud Drive on your macOS.
Once iCloud Drive is enabled on your macOS, you can access it using the Finder. You can now copy files to iCloud drive as you usually do with any other folder or drive.
The iCloud drive path on macOS is:
~/Library/Mobile\ Documents/com~apple~CloudDocs/

So if you create a folder called dataset in iCloud drive, it's path will be
~/Library/Mobile\ Documents/com~apple~CloudDocs/dataset

You need to use this as the startup folder for your Jupyter notebook as described here - Access iCloud Drive in Jupyter Notebook.