How to enable confirmation alert when using 'rm' command to delete files / folders?

You can use the -i flag:

rm -i someFile.txt

If you're concerned you may forget to do this, you could alias the rm command:

alias rm="rm -i"

If you place this alias in one of the files sourced when you start a session (e.g., .bashrc), you'll have it available in all your future terminal sessions.

You want to use rm -i or rm -I

According to the man pages: man rm

-i prompt before every removal

-I prompt once before removing more than three files, or when removing recursively. Less intrusive than -i, while still giving protection against most mistakes

As above or perhaps

alias rm="rm -i"

But be careful doing this if you use multiple accounts and one does not have this alias