Im going to attend Santa monica college and im sort of confused on what to major in.?

I want pediatric nursing but dont know what type of nurse. I want to become a nurse that is similar to a doctor and one that has a good salary. Im also in between a peditric nephrologist aswell. I am diagnosed with pkd so i have an interest in that aswell. what classsses do i take to become a nephrologist and how long does it take