You verify that your computer hardware, software applications, and peripheral devices are all compatible with the new OS.
In some cases, if there is an upgrade solution for your 3rd party software applications and peripherals, it may not be free.
At the moment, the GreenPrint application is not working with Ventura. ITC is investigating, but if you are a student and use the GreenPrint application, you may want to hold off. GreenPrint Mobile and Send Document to Printer through the network should still work as expected, though.
Submit a ticket for a consultation about when to upgrade
If you are currently running macOS Mojave 10.14 or older, there are some important changes that came with macOS Catalina, 10.15, that also apply to Ventura.