The simplest test possible is to submit a job that simply runs the "set" command, which does nothing but print out the operating system's environment variables. You can see what it's expected to do by opening a cmd prompt on Windows or a Terminal on OS X and simply typing
set and hitting <
Start the Qube! UI, and select the Submit->Tests->Test 'set' job menu item.
Then, just click "Submit":
Go to the Jobs Panel in the Qube! UI, and you should see the job in the list (it will be named "Qube Test 'set' Job"). After a short period of time you should see the job in a "Complete" state.
Note that the ID of your job will be different from the screenshot above.