When your trip is finalized (in the "booked" or "approved" status), you will get a confirmation email with a PDF that includes your full itinerary. The confirmation email has everything you will need for check-in including an eTicket, airline confirmation code, and PNR. If you book from a low-cost provider, the final confirmation email may take a few hours to arrive in your inbox, so don’t be alarmed.
There's no need to print anything for your trip, as it's all available in your confirmation email and GetGoing site. If you prefer to have a printed ticket, most airlines have printing kiosks available at the airport.