Dear Rosetta Kosch,
Thank you for posting in Microsoft Community. We are happy to help you.
I recommend you try MVP Jim' suggestions.
If you still cannot use AutoUpdate tool to update Word, you may also try directly downloading the latest version 16.77.1 Word from this package: Update package
Here is a support article for reference: Update history for Office for Mac - Office release notes | Microsoft Learn
Welcome to post back if you have any concerns, I'll be glad to help you further.
Have a nice day!!
Sincerely,
Tina | Microsoft Community Moderator