You can download the latest version of Blender at http://blender.org/download. At the time of writing, the latest version is Blender 2.83. Blender is available on Windows, macOS, and Linux. It is a very similar experience on all three operating systems.
Most of Blender's hotkeys are the same between operating systems. However, if you are following along with this book using a Mac, you need to use the command (cmd) key instead of the control (ctrl) key any time the instructions say to use the control key.
Before we learn about the current version of the user interface, it's useful to know a little bit about Blender's history. There is over a decade's worth of tutorials and resources available online. The software may look a bit different in those old resources, but if you can get past the old interface, the information is just as...