Question: how to connect one airpod to a new case?
Answer: Put both AirPods in your charging case. Open the lid and check the status light. It should flash amber. Press and hold the setup button on the back of the case for a few seconds. ...  On your iPhone, go to the Home screen. Open the case—with your AirPods inside—and hold it next to your iPhone. ...  Tap Connect, then tap Done.