In this short post, I'll go over where to get more information on installing git on your machine.
To install git, go to https://git-scm.com/. Here you can download git for the type of machine you've got (Windows, Linux, Mac). This site will also provide you with information on how to install and setup git properly on your machine. It will also provide you with some other useful git clients that are good to use.
Assuming this will be your dev machine, I'll strongly recommend you add git to your PATH, this makes life really easy.
To test the installation, open up your terminal OR command prompt, then type
git --version. This should display the current version of git that you're running.