If OneNote is not allowing you to delete or move a selected page, your first step should be to troubleshoot the issue. Here are some things to try:

1. Check that the page is selected: Make sure the page tab is highlighted before attempting to move or delete.
2. Check the page structure: Is the page you are attempting to delete a child page? If so, you may need to delete from the parent page.
3. Check that OneNote is up to date: Ensure OneNote is up to date. Sometimes older versions of the app will not allow for certain functions.
4. Restart OneNote: Quit and restart the OneNote application. This sometimes solves minor issues.
5. Check the OneNote cache: Sometimes the OneNote cache has to be cleared to remove any minor issues.