Oh my zsh.

Install ZSH.

sudo apt install zsh-autosuggestions zsh-syntax-highlighting zsh

Install Oh my ZSH.

sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

Install plugins.

• autosuggesions plugin

  git clone https://github.com/zsh-users/zsh-autosuggestions.git $ZSH_CUSTOM/plugins/zsh-autosuggestions

• zsh-syntax-highlighting plugin

  git clone https://github.com/zsh-users/zsh-syntax-highlighting.git $ZSH_CUSTOM/plugins/zsh-syntax-highlighting

• zsh-fast-syntax-highlighting plugin

  git clone https://github.com/zdharma-continuum/fast-syntax-highlighting.git ${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/plugins/fast-syntax-highlighting

• zsh-autocomplete plugin

  git clone --depth 1 -- https://github.com/marlonrichert/zsh-autocomplete.git $ZSH_CUSTOM/plugins/zsh-autocomplete

Enable plugins by adding them to .zshrc.

• Open .zshrc

  nvim ~/.zshrc

• Find the line which says plugins=(git).
• Replace that line with
  plugins=(git zsh-autosuggestions zsh-syntax-highlighting fast-syntax-highlighting zsh-autocomplete)

References

• Oh my ZSH
• zsh-autosuggestions
• zsh-syntax-highlighting
• zsh-fast-syntax-highlighting
• zsh-autocomplete