Should I work as either an RN or respiratory therapist before becoming a Physician Assistant?

Hi I'm a junior in high school right now and I'm starting to look at what I want to major in during college. I've decided that I want to become either an RN or respiratory therapist for a period of time to take care of the hours needed to be a Physician Assistant, get experience,and pay some student loans :/ Which career would be more beneficial to me in the long term? And what should I major in in college to become a respiratory therapist? Thanks for your help!:)