Upgrade or update.
First download and install the update of for the stable release:
Combo update 10.14.6 https://support.apple.com/kb/DL2010?viewlocale=en_US&locale=en_US
If this is your issue, then from SafeBoot, both download and install:
If you want to upgrade from there after the fact, verify you have a current backup plan, then reference:
Typically you are always better off running the most current macOS your machine will allow—especially for the built in security features.
Old app compatibility maybe one reason to hold back— you have to do your own homework here: https://roaringapps.com/apps
32-bit app compatibility with macOS ... - Apple Support
https://support.apple.com/en-us/HT208436
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https://www.apple.com/macos/catalina/
https://itunes.apple.com/us/app/macos-catalina/id1466841314?mt=12&l=en-us
macOS Catalina - Technical Specifications - Apple Support
https://support.apple.com/kb/SP803?locale=en_US
System requirements macOS 10.15 Catalina
macOS Catalina will run on all Macintosh computers that supported Mojave:
MacBook: Early 2015 or newer
MacBook Air: Mid 2012 or newer
MacBook Pro: Mid 2012 or newer
Mac Mini: Late 2012 or newer
iMac: Late 2012 or newer
iMac Pro
Mac Pro: Late 2013 or newer; Mid 2010 or Mid 2012 if upgraded with a recommended Metal-capable GPU