Lost Pages file

If you did not manually save the initial Pages Untitled document and give it a meaningful name so it could be autosaved, then that unsaved content is gone when you quit Pages and will not appear in the Recent menu or anywhere else. It is vaporized and no means to get that content retrieved.

The first thing that I do when I create a new Pages document, even while it is blank, is to manually save it. Allow for the fact that Pages will continue to use the same save location with new documents until you change it.