how do make a folder for specific saved documents

Go to the Files app. The select On My iPad or iCloud Drive on the sidebar. Then find an empty spot and hold down a finger until you see it say "New Folder". It will be titled "untitled folder" but you can change the name.

The iPad User Guide is a rich source of information about iPad and its many features and functions. Here is direct link to the relevant section of the Guide that describes file and folder management:

Organize files and folders in Files on iPad - Apple Support