macOS

I think that Catalina is the latest macOS for your computer.

https://support.apple.com/en-gb/HT210222

The Big Sur compatibility list is below. It doesn't include any computers from 2012, though.

https://support.apple.com/en-us/HT211238

You may hear stories about patched versions of macOS which will allow you to install a later version on your Mac. You could try doing this but if you succeed, not 100% of all facilities would work on your Mac. You might find that your Wi-Fi adapter is disabled. After this you could try using a USB Wi-Fi adapter.

How to get Older versions of macOS. Be sure to Open links in Next Page using Safari as Others may not work. Also, verify if this computer qualifies for any newer version of macOS. Think this machine can move to Catalina and not further.

Special Notation : If going to Catalina - it does not support anything, Apps, Drives or extensions 32 Bit. Everting Must be 64 Bit or it will not work. Much like Big Sur - worth reading over here Before attempting the upgrade to any newer version of OS