Step 1: Install VirtualBox
This one’s easy. Head over to the Downloads section on the VirtualBox site and snag the appropriate installer for your OS. Since it will be a little different for each OS, I won’t provide screenshots for each step here. In general there’s just a lot of “Next” clicking involved. Of note, the networking component of the setup process will temporarily disrupt your connection. So if you’re downloading anything else, wait until it is finished before continuing with the setup.
Once installation is completed, you’ll be greeted with a screen like this the first time you run VirtualBox: