From the box to a live order: where the printer stands, what it needs plugged into it, how it learns which counter it is, and what to test before doors.
A ticket printer has one job at a counter, and most of whether it does that job well is settled before it is switched on. Stand where orders are actually assembled and find a flat surface within arm's reach of that spot - not the far end of the counter, and not behind somebody's back. A ticket is read, torn off and carried to the cup, bag or tray it describes, so every extra step between the printer and the hands is one that gets skipped once the counter is busy.
Keep it clear of the three things that ruin thermal printers: splash from taps and sinks, heat from a grill or a fryer, and the dust of an outdoor site. Leave room for the roll door to open all the way, because that is a hatch somebody has to lift one-handed mid-service. Then check that power and the network both reach the spot without a cable crossing anywhere a person walks.
Thermal paper prints on one side only, so a test ticket that comes out blank usually means the roll is in upside down. Turn it over before looking for a cleverer explanation. Close the door until it clicks, tear the first length off square, and make sure the roll width matches what the printer expects, or tickets print narrow with the guest's name running off the side.
The other half of setting up a printer has nothing to do with the printer. In the system it is a destination with a name, and that name should be exactly what the counter is called on the floor and on the plan. Assign the items that counter makes, and a paid order for those items has somewhere to go. Get the name wrong and the hardware works perfectly while tickets appear in the wrong building.
Give each counter its own printer rather than making two counters share one. A shared printer turns every ticket into a question about whose it is, and it makes one unplugged cable into two counters gone quiet at once.
Print a test ticket, then read it standing where the staff will stand, in the light you will actually have. The guest name should be legible at arm's length without leaning in, the item and any note under it readable at a glance, and the cut clean enough that the ticket does not tear across the name.
Then put one real order all the way through before doors: place it the way a guest would, let it route on its own, and watch it print at the counter it belongs to. That is the only test that proves the whole path, and it is worth repeating after anything moves - a new menu, a counter in a different marquee, a spare printer.
A printer is set up when a paid order reaches it without anybody carrying a message, and when somebody notices within a minute of it stopping. Until both are true, the counter is relying on being watched.