I’ve had some training in driving an emergency vehicle and I’ve been in the passenger’s seat a few times, so I know that the one thing the ambulance driver wants is predictability. Do whatever you can to safely get out of their way. Usually that means moving over to the side of the road and slowing down, but if it’s really slow traffic you might have to stop. Whatever you do, don’t stop while you’re in their way.

Tldr: stay calm and use your common sense.