What is the operating range of AirPod Pro

Apple does not provide an official operating range for their AirPod Pros, except that they are Bluetooth 5.0 devices, like your iPhone X. In theory, BT 5 devices have a maximum range of 240 m/800 ft. This range is also directly affected by interference. Regardless, you may find that you can get 100+ feet between these devices, but I would suspect that between 5-30 feet is where you would most likely find them usable.

That depends on environmental factors.

Walls, microwave ovens, etc will interfere with the signal.

I don't own Airpods of any kind but I can leave my phone in my house and walk out on the porch and still receive a clear connection with Sony in ear Bluetooth headphones. About 60 feet.