1) On a web browser (on a computer, not on an iPad) go to iCloud.com
2) sign in with your Apple ID and password.
3) Once you are signed in, select the orange Pages icon.
4) If there are welcome screens, continue until you get to Pages web version
5) Are your documents showing there?
If yes, delete Pages app from your iPad, and reinstall. Your documents should reappear when you open Pages after installing. (Ensure in Settings, iCloud, Documents & Data, that Pages is swiched on.)