Add folder to Home Screen

I'm not entirely certain what you are attempting to achieve...

If you refer to a file/document folder that you can access using the native Files App, the no - you cannot add these folders directly to your iPad Home Screen.

You can, however, create a Shortcut to a file or folder using the Shortcuts App - and add the Shortcut itself to a Home Screen. The Shortcuts User Guide provides information and appropriate guidance:

Add a shortcut to the Home Screen on iPhone or iPad - Apple Support