EMT is essentially a better structured form of basic first aid. Some states let you do things like IVs, or even advanced airways, but for the most part they don't. You'll learn your the structured methods of assessment, treatment, anatomy & physiology, and a tiny bit of pharmacology. The one thing they tend to forget to teach you is the more important customer service and human interaction skills you need to be a good provider. Classes are fun, just make sure you study, and get as much hand-on experience in practicals and ride-alongs as you can.