Hi Kaydee.
Windows update is saying "end of service" likely because you are using an older version of Windows that is no longer supported. That doesn't mean you cannot update Windows (unless your computer is a decade old). It just means you should update Windows. There may be a button that says "Check for updates" under Windows Update in Settings.
See screenshot below for guidance.
On my laptop, I now see that Windows 11 version 24H2 is available. I can download and install it when I'm ready to do so.
Otherwise, what you would (should) normally see on this page are one or more smaller updates listed. Once a month, on the first Tuesday, Microsoft will release its monthly updates for Windows 11 (and Windows 10). It is possible to pause the updates for one more more weeks, if one is not ready to install updates right away.
Be sure to backup / copy your personal files to a cloud service like OneDrive, or copy them to an external drive for safe keeping, as a precaution.
If you are still running into a problem with Windows update and discover you simply can't update, you might consider taking the computer to a local neighbourhood computer repair shop. They can assist you.
Screenshot: