Hi, Michaela,
From your e-mail address I guess you live in New Zealand, and I am sorry but I am not familiar with the requirements for veterinary studies in NZ. You will certainly have to go to a Univeristy which has a veterinary school, and the course takes at least 5 years.
Your school Head Master or Headmistress should be able to advise you, or to find out the information you require.
W