Paralles newbie here, requesting help in plain language. I'm currently running Mojave, thinking of upgrading to Catalina, and want to be able to run Mojave after I upgrade. How do I obtain Mojave? Is it still available from my recovery partition, or would Apple provide Catalina via that route because it's the current OS?
Yes. See the link provided and go to the "Installing macOS Mojave virtual machine after upgrading to macOS Catalina". There is a link to Mojave OS download. https://kb.parallels.com/124786