I do not like to retype fish every time I start terminal. I want fish on by default. How can I set fish shell as my default shell on a Mac?
the chsh program will let you change your default shell. It will want the full path to the executable, so if your shell is fish then it will want you to provide the output given when you type which fish.
You'll see a line starting with "Shell:". If you've never edited it, it most likely says "Shell: /bin/bash". Replace that /bin/bash path with the path to your desired shell.