Zsh is an alternative to bash. Check out the Arch wiki first.
We have a script to install zsh. But not only zsh also other features that are need to have like
Command not found has been abandoned in Feb 2018.
You will find it on all githubs : https://github.com/arcolinuxd.
After running the script you need to change the shell with this command
sudo chsh erik -s /bin/zsh
Change erik to your loginname.
Then we reboot and check out our terminal.
We need to get the aliases from our .bashrc and copy/paste them into .zshrc.
We reload the .zshrc with the command source.
Getting back to bash if you are tired of using zsh is done like this
sudo chsh erik -s /bin/bash