NGC-installed Catalina on Mac, now Finder can't see files or folders

[SIR REAL ED]

Hi Gang,

Against my better judgement, I upgraded(?) the OS on my Mac to Catalina 10.15.1.  Now when I use Finder to look at Desktop or Documents, neither folders nor files show up.  Files do show up under Applications, Downloads, and Recent.  If I use the search function, the files are there, I just can't access using my normal habits.

Using google reveals this is pretty common, but fixes seem widely varied, and the authors are using a lot of terminology I do not recognize.

Thanks in advance.

Ed