Hi,
Just for confirmation:
Do you have Multitasking set to Windowed Apps or Stage Manager in Settings ➜ Multitasking & Gestures?
click here ➜ Multitask on iPad - Apple Support
If so, tap on the "Pages" text near the top left corner of the Pages app window to bring up the Menu for it. Then go to the Window menu and tap on New Window. select yout other file to open. with both files opened tap on the colored bubbles at the top right corner
and then tap and hold on the green one to bring up the multi-tasking options Split view is the one with the black rectangles on each side. Select one or the other to dock the window on one side or the other, then repeat the process for the other window.
