OKAIDI kits arrive with camera and monitor already paired, so “setup” mostly means placement. Here is the order that works.
The monitor ships partly charged; give it a full charge before the first night so the battery meter calibrates. The camera does not have a battery: it lives on wall power.
The lens wants to look down into the crib at roughly 45 degrees. Just above the rail is the sweet spot, which is what the clamp mount is for; on a dresser, the weighted stand lifts it over bumpers and toys. Keep every cord at least three feet from the crib.
Use the pan-tilt arrows on the handheld to trace the room’s corners. If the camera can cover the crib, the door and the floor without hitting its stops, the spot is right. Set the 2x zoom on the crib for night use.
Out of the box the screen stays on and the battery gives about 16 hours. In ECO (or VOX on that variant) the display sleeps until sound wakes it, and a charge stretches to roughly 30 hours. Most owners never switch back.
Take the handheld to the far ends of the house, the yard and the garage. Where the link drops, you have found your real indoor range; anything inside it is fair territory for laundry, work or dinner.