There is a Online Shop sample application in the Getting Started pages with a business process. You can also access it directly from the Service Studio introduction screen.
Check it out and see if it fits your expectations.
I suggest you follow the Agile Business Process tutorial, here, or the Developer Course III on Business Processes, here. All your questions (and a the ones to come that you will have) are explained in those resources.
But answering directly to your specific questions:
Hope this helps. Cheers,