Installing Unity
Putting Unity to use in practice is a simple matter of checking the right boxes.
First: Install Microsoft Visual Studio (abbreviated ‘VS’) on your workstation. Your first installation will probably not include all the computer language and framework options you want. Simple rely on the VS Installer to add as you go along. (There does not seem to be an option for removing installed development tools.)
The game development two options are available mid way down the list:
The Unity Installation is done after the Visual Studio installation. It is rather intuitive, until making the correct choices of add-ons.
Android Build Support
openJDK
Android SDK and NDK Support
Next are the lesser-known resources to include in the Unity install:
WebGL Build support
I include here the link for further study of WebGL:
https://get.webgl.org/ and https://www.khronos.org/webgl/wiki/Tutorial
Windows Build Support IL2CPP
Precompiling gaming code into C++ on Windows is the remaining introductory option.
There is substantial documentation for each piece. I hope this is of some help.