Don't think there is a 2019 Mac Mini. The latest ones from Apple are 2018.I don't have much software anyway, mainly Apple stuff like Pages. Mainly use my 2019 Mini for web surfing
Also, assuming you run no third party software, you should be able to "move" to Catalina without issues. But, it is of course mandatory that you are making backups. And if you are, and based on what you said above, I suspect you are using Time Machine for that task. Correct?