Update Macbook pro with retina (2012) when no updates are currently showing. Have not updated for 5 years

The highest version of MacOS that can run on a mid-2012 MacBook Pro is Catalina:

https://apps.apple.com/us/app/macos-catalina/id1466841314?mt=12

Download macOS Catalina 10.15.7 Update

One should always update the OS to a newer version whenever possible. As your MacBook is 2012, it is somewhat too late to start upgrade. Anyway, Google how to update a 2012 MacBook, you might get an answer/solution. Good luck!