see freecodecamp.org
brew cask install iterm zsh
if on an actuall mac Os (catalina) zsh is not required
for better zsh configuration, install Oh My Zsh
sh -c "$(curl -fsSL https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)"
upgrade_oh_my_zsh
gets you the latest version
edit ~/.zshrc with preferred text editor
install powerlevel9k theme into oh_my_zsh
git clone https://github.com/bhilburn/powerlevel9k.git ~/.oh-my-zsh/custom/themes/powerlevel9k
get the fonts ready for powerline
git clone https://github.com/powerline/fonts.git
cd fonts
./install.sh
make sure to enable ligatures in iterm as well as changing the default font to now installed powerline font