A:AnswerAt the fist boot you will be presented with an option to import your old mac data or recover from a time machine backup. Just be aware Catalina no longer supports 32 bit apps, so most the older apps will not work unless they have updates for OSX Catalina.
A:AnswerI would venture to say that if there is an HDMI on the monitor then you should be able to plug it into the Mac Mini's HDMI port. The Mac Mini I'm referring to is the "Apple - Mac mini Desktop - Intel Core i3 - 8GB Memory - 256GB Solid State Drive - Space Gray", which is the 2020 model running Catalina.