How do I back up files on my iPad to a USB thumbdrkve

Hello photo31man,

If you're looking to make a full backup of the iPad, the available options will be to back up to iCloud or to a computer. This page helps to go over them: Back up iPad - Apple Support

If you're just looking to instead connect the USB drive to manage some files between the iPad and the USB drive, you can first find info on connecting the drive here: Connect external storage devices to iPad - Apple Support

This page has some info on using the Files app that may help: Use the Files app on your iPhone, iPad, or iPod touch - Apple Support

Note that you may long press on a file in the app to select options like Copy/Move/etc.

Cheers.