I am sorry you are having printer problems. If you will bear with me, I will offer some things to consider. Whenever we install an operating system upgrade or some OS updates, some printers and scanners will often stop working. Then a new OS compliant printer driver must be installed. Providing up to date printer drivers is the responsibility of your printer vendor and it is not Apple's fault if they fail to do so. Experience has shown that many printer manufacturers are very slow to provide updated drivers. Drivers for some older printers are never provided. (Apparently, they prefer to sell new printers.) What we can do is to thoroughly check the printer web site for an updated driver that works. If one is not available, then we should ask when one will be released. If that doesn't work, if the Printer has the Air Print feature, that can be used and no driver will be needed. If not, then you can check the web site below where volunteers write drivers for older printers which are no longer supported, but which work with newer operating systems. It is worth checking out. Good luck.
Gutenprint Supported Printers
Incidentally, since you have Catalina installed on a back up drive you can print immediately by merely selecting that drive as the startup drive and using it for the time being. Problem solved.