where, on my ipad, are documents and data storef?

Hello,

Most documents are stored in iPad’s Files application. Storing documents in iCloud Drive can free up iPad’s storage. When iPad’s storage becomes full it will offload any local copy of a document stored in iCloud Drive.

Each app has its own protected file storage space. Often those can be accessed through the Files App. But there is no user accessible, nor cross-app integrated file storage system in iOS.