Windows Upgrade Help and more

Same here. Oh, and just a heads-up, sometimes you need to restart your PC or File Explorer for the new icon to show up properly. Hope that helps.

You could also check if there's a "CSM" or "Legacy Support" mode that needs to be disabled first, as that often hides the Secure Boot option.

Yeah, You could also run the Windows Update troubleshooter, since that error code is often tied to permission issues during an update.

Yeah, and it's a good idea to check your specific Windows version in Settings > System > About, since dates can vary a bit by edition.