You can refer to the example shell scripts shipped in the /home/user folder on the Ubuntu VM.
% cat /home/user/start-gazebo-office.sh
To learn more, you can refer to this tutorial that explains some basic concepts about Linux shell scripting. In the Ubuntu VM, desktop shortcut icons are used to call these individual shell scripts. You can refer to the ubuntu forum page to learn more about creating / customizing your own desktop shortcut. See a shipping desktop shortcut on the Ubuntu VM for reference.
% cat /home/user/Desktop/start_gazebo_office.desktop