Renaming files in Catalina on my Mac

Catalina didn't change how you rename files. One method is to open Finder and control click on the file and then click Rename.

Another is to highlight a file in Finder, wait a second and click on it and it will change from dark blue to light blue and you can then enter a new name.

The same way you have before with some exceptions -- you can't change anything in the root filesystem for example, only in what is considered the "user" portion, like /Users and a few others.

Do you get some sort of error or what happens when you try. More details are needed please. Some explicit examples would help in giving more advice.

Good luck...

What are the permissions on the file? Do a "Get Info" or command+i on that file -- do you have permission to write? Permissions are at the bottom - you might have to click the triangle icon to expose this info.

Good luck...