Ordinarily Terminal doesn’t obey the usual Option (Alt)+Delete keystroke that deletes a word behind the cursor in other apps. To make Terminal do so, hit Escape, then hit Delete. You will need to do this for each word you want to delete - Escape, then Delete; Escape, then Delete; etc.
If you’re editing a file in nano, emacs or vim, you can hold down Option (Alt) then click anywhere in the file to move the cursor there. It works at the command line too - you can jump to anywhere in the line you’re currently typing by holding down Option (Alt) and clicking there.