I want to work with animals when I'm an adult?

I'm a freshman (home schooled) in high school, and my dream is to travel the world, working with animals in the field and helping endangered species of wildlife, whether to maintain their habitat, raise orphaned animals to be returned back to the wild, etc. I really want to work in exotic locations such as Africa and South America. Mainly, it may sound corny, but I want to make a difference and change the world. Should I get a degree in zoology, biology, wildlife management? What career should I look into once I get my degree? And what sort of salary do zoologists usually make? As far as biological careers with the government, what exactly do you do? Steve Irwin, Jeff Corwin, and Saba Douglas-Hamilton are all huge inspirations to me, but I doubt I'm going to have my own wildlife TV show, so what would be a good alternative career that involves travel, exploring and adventure? How does one get employed by BBC, National Geographic or WWF? Sorry I have so many questions, I'm just really curious and confused as to what would be the best path for me. Thank you!