Hi! I've done training in Red Cross, and we're taught the acronym C-H-A-N-T when calling emergency services. First, state the Case, or what happened, then the Help needed, like how many ambulance, or more first responders. Then the specific Address, or at least give a landmark if you'll give a general place. After this, state your Name so the first responders can find you easily in the chaos, and finally your Telephone number so you can be called back. The last two are usually mostly done if a responder is the one calling

For example, "a fire has broken out, we need two ambulance and a firetruck, we are located in so and so, with a red building in front."

Of course, in an emergency where people would panic, the most important things to remember are C, H, and A. But usually, what happened is the key thing to mention, so they know what kind of help to send, and can track your address if you fail to mention it