how to uninstall the 32-bit software on macOS Catalina?

Even though they're inert, those apps occupy storage space and it's understandable if you want them gone.

You can simply select one of those 32-bit apps in System Report, and its Location will be revealed.

Select the entire line adjacent to it, then two-finger tap (or control-click), and select Services > Show in Finder. That will open a Finder window with that file selected. Drag it to the Trash, and you're done.

It is not necessary to uninstall any 32-bit software. It will not work any more, and isn't affecting your Mac.

If you know what it is you want to remove though, simply drag it to the Trash. It's inert. If you don't know exactly what to remove, explain how you found it and perhaps someone can offer assistance.

There is no need to create a new Apple ID just to post a question here.

I recommend not creating multiple Apple IDs, because it is likely to result in your own inconvenience, and probably confusion as well. Use the same Apple ID as you use for everything else. One person, one Apple ID.