my computer is saying its unable to update?

Silver174 wrote:

unable to check for updates.

Can't connect to the apple software serve.

Any idea how to update my Mac?

Big Sur macOS 11.6

https://support.apple.com/macos

The older macOS installer backups on this server:

https://support.apple.com/en-gb/HT211683

verify you are using the Safari browser to download/initiate the macOS links.

Silver174 wrote:

unable to check for updates.

Can't connect to the apple software serve.

Any idea how to update my Mac?

This might be an indication of a piece of Malware or Adware that is interfering with the connection to the Apple Apps Store.

Suggest downloading from a Respected ASC Contributor the application Malwarebytes for Mac. It is free or paid for added features. Run the Application and it should remove the malware / adware. Once done, restart computer and test.

There are no known Windows-like Viruses in the wild that self replicate and affect macOS, because of the underling UNIX  Foundation and Permission Limitation. 

There are Malware-viruses and Adware-viruses that does affect macOS and are often times downloaded as part of an Application from Third Party UnTrusted Site and get installed along with the Application.