Hello Bud in PA,
We appreciate you reaching out to us about this matter and are here to help. We would like to ask you a couple of questions in order to get a better understanding. First, what exact version of macOS are you currently using? We ask as the menus and options can change slightly between versions of the OS, and we want to make sure we provide the most accurate steps. You can locate this by going to Apple menu  > About This Mac. Also, when you reference iCloud D&D are you referring to iCloud Do not Disturb? To answer your question, you can have an external HD connected to your device and use Time Machine backup. Check out this link for details on this feature: Back up your Mac with Time Machine - Apple Support
You also can upload your files to iCloud Drive by following these steps:
Upload files:
In iCloud Drive on iCloud.com, do either of the following:
- Drag files from the desktop or a folder window on your computer to the iCloud Drive window or a folder icon in the iCloud Drive window.
- If you drag to a folder icon, it becomes highlighted to confirm that the item you’re dragging will go into the folder.
- Click in the iCloud Drive toolbar, select the files you want to upload, then follow the onscreen instructions.
Some apps, like Pages, Numbers, and Keynote, have their own folders in iCloud Drive. You can only upload a file into an app’s folder if the app can open the file.
We recommend checking out this link for additional information on uploading and downing files to iCloud Drive: Upload and download files from iCloud Drive on iCloud.com - Apple Support
Kindest regards!