mid 2012 MacBook pro no software update
I do not have "Software Update" in System Preferences. How can I get Mohave? I am running High Sierra 10.13.6.
MacBook, OS X 10.10
You can access the macOS installer links to 10.14 and 10.15 using the links in this Apple article which also includes optional instructions for creating a bootable macOS USB drive:
https://support.apple.com/en-us/HT201372
Make sure to have a good backup before attempting to upgrade macOS.