How to set zsh as standard shell in Ubuntu

Install zsh

sudo apt install zsh

Add zsh to list of valid shells

sudo vim /etc/shells

Add to the list

/usr/bin/zsh

Set zsh as default shell

chsh -s /usr/bin/zsh

Double check

$ echo $SHELL

Now you might want to check out https://ohmyz.sh/#install to install a nice theme.