Check with your local fire department or employer ( larger companies) I had to get fire extinguisher training every year for my job. Perhaps there’s a training course that you can attend. Ours consisted of a video about types of fires and extinguishers. Then we had hands on a cut down barrel with some lit diesel fuel Twist pin, easier then pulling aim at base of fire squeeze and sweep flame. https://youtu.be/ktrv34zW7-A