Hey there David_1657,
Thanks for reaching out to Apple Support Communities. I understand you’re having issues with the ‘Upgrade to iCloud Drive’ box on your iPad and iPhone. I’ll be happy to help.
If you haven’t already, force close the Settings app and restart your iPhone and iPad:
• How to force an app to close on your iPhone, iPad, or iPod touch
• Restart your iPhone
• Restart your iPad
Then try upgrading iCloud Drive once more.
If that doesn’t work, try upgrading from a computer. You can do this either with a Mac, PC, or at iCloud.com via a web browser. Take a look at this link for more info:
• Set up iCloud Drive
If you don’t have access to a computer where you can do this, on just your iPhone only, back up and reinstall iOS using the steps from these links:
• How to back up your iPhone, iPad, and iPod touch
• If you can't update or restore your iPhone, iPad, or iPod touch
Try enabling again and if it works, attempt from your iPad once more and see if the issue is resolved.
Regards.