In this post I'll provide you with step-by-step tutorial on how to set up oh-my-zsh in your terminal with in my opinion, essential plugins.
First things first:
If you run Linux you can use your packet manager to install all neccesarry packages and jump straight to configuration section.
Instead of apt install use your packet manager commands.

Linux install using packet manager

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

Terminal install using Git and sh

• 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
  

Configuration

• Enable plugins by adding them to .zshrc.

  • Open .zshrc
  • nano ~/.zshrc
  • Find the line which says plugins=(git).
  • Replace that line with

 plugins=(
  git
  zsh-autosuggestions
  zsh-syntax-highlighting
  fast-syntax-highlighting
  zsh-autocomplete
 )

• Reload your environment to make changes work!
  • source ~/.zshrc

Optional

• Enable cutom theme
  • nano ~/.zshrc
  • Find the ZSH_THEME="robbyrussell"
  • Replace with ZSH_THEME="alanpeabody"

You can find my fork of the file on Github Gists