Did the shell ( terminal ) change in Catalina?
Your shell has been changed to Zsh, which is the default for new users on Catalina (10.15) and later. To go back to the old shell (BASH), run chsh -s /bin/bash (chsh is a "Change Shell command, the -s flag is "set", and /bin/bash is the location of the BASH shell). Then close and re-open terminal, or log out and log back in, and your shell will be bash again.

Alternatively, if you want to use the GUI, open System Preferences, Users and Groups, unlock the padlock at the bottom left, and control-click or right click on your user. Then, select "Advanced Options." There should be an entry called "Login Shell", which you can set back to /bin/bash.

Source: How to set shell in OS X - Super User