Trying fish without the burden of changing your current terminal is useful incase you do not like Fish terminal
1. First you need to install Fish
Checkout my other detailed post about installing fish terminal if you do not have it installed.
2. Try Fish terminal
You can then try it in your current terminal by typing the following
Success you might notice your current terminal looks a bit different. This is because you are now in a fish terminal. To exit this either close the window or type
bash (or whatever terminal you came from).