The basic way is to launch the virtual machine and a window is created.
This will prompt for username and password. (root, puppet)
Sometimes this virtual machine window will be too restrictive (no functionality to scroll up to review past outputs, resize the window, etc.)
Therefore the alternative method is offered for Linux users, to use the Linux shell:
This is assuming 192.168.56.100 is the name of your virtual machine, it may have changed.
You will then be prompted for the password: puppet.
After this you will be able to issue commands as specified elsewhere that will interact with the server.
To quit the server environment, use Ctrl+D or issue command exit .