What is it like being a Health Care Specialist?

I am interested in taking up this career and I want to know from personal experience what this job is like, the schedule, what you do daily, the chances of going into combat (I'm a female), what occupations I can get after I retire, what is my training, how "durable" do I need to be, and what are some classes I should take in high school to prepare myself. Anything will help tho. Any advice too. Thank you(: