Hi thomasg64291783,
If you uninstall Acrobat (or any other iOS app), the operating system will erase all of app data (including your documents and preferences).
Is it possible that you saved documents in cloud storage such as Adobe Document Cloud or Dropbox?
If you re-install Acrobat and sign into Document Cloud and/or Dropbox, you should be able to see your cloud documents in Acrobat. Please tap "Files" in the bottom tab bar and go to "Locations" and select Document Cloud or Dropbox.
If you have iCloud backup for your entire iPad, you can restore from iCloud.
Restore your iPhone, iPad, or iPod touch from a backup - Apple Support
I'd highly recommend backing up your device and/or documents regularly using iCloud or iTunes.
How to back up your iPhone, iPad, and iPod touch - Apple Support
How to back up and restore PDF documents on iPad/iPhone using iTunes
I sincerely hope that you find the backup copies of your deleted documents.