To download the Visual Studio Community 2017 installer go to https://www.visualstudio.com/vs/ community/.
When you click on the Download Community 2017 button, your browser will download a 1 MB file called vs_community__1698485341.1480883588.exe. When you run this application, it will allow you to specify the languages and libraries that you want installed, and then it downloads and installs all the necessary components.