What kind of course do i have to take if i want to be major in Biology and Geography?

When i grow up i want a job related to nature no matter if the pay was good. maybe something like a volcano researcher, snow researcher, snow mountain guide, conservationist, dolphin trainer, marine biologist, park ranger, fauna researcher ect. I have keen interest in these two subjects Biology and physical Geography which i believe would lead me to the job i have to have in the future. what course must i take to be major in them? and what route must i take to have one of these jobs? or what must i do to have one of these jobs?robably the higher pay ones hahahah. i lover lots or hands on and i hate sitting in the office. do i need a masters or even a PhD?