Wax, grease, oil --- the only extinguisher is to remove the air by covering it. Either with a lid that fits the pot or a fire blanket. (other non-flammable blankets can do the job, make sure what you are using doesn't combust)
Spraying a burning pot with any extinguisher will stir up the surface and spread burning wax, grease or oil all over, creating a much larger fire than just leaving it burn would have. If you can't safely cover the pot, get everyone out of the building and call 911 in that order.
Wear protective clothing. There are lots of resources that tell you what to wear. But to keep it simple, don't wear fabrics like polyester that melt. They melt right into your flesh. Don't wear fabrics that burn easily. Generally cotton or wool are a reasonable choice. No bare arms. If you do have a fire, how would you put the lid on it safely if your arms are bare? Gloves at hand would be a good idea too. If you aren't wearing them, stop to put them on first. Above all, keep your head and don't panic. Panic maims and kills. Move slow and deliberate, keep control.
A face shield is a good idea too, though many people would think that is overkill. A splash of hot wax on your face, espeically near your nose and eyes is going to be a lot more painful than on your hand and will cause an immediate reaction (backing up and tripping over the dog) that could do a lot more damage.
Safe work habits will help you enjoy your work and help to keep you out of the hospital.