If you want to be a firefighter, I would suggest trying to get involved with a local volunteer fire station. I'm not sure if there are many near you, but they are a good place to start. CPR certification and any other basic training along those lines is a big plus. Many firefighters are also required to have EMT or Paramedic status so there will be some medical care requirements typically. As for the animal vet, classes in Biology and other sciences provide a good background. Again, look for opportunities to get experience in the field you choose.