Humanitarian work - how do you do it?

Good morning! 

I've been reading different posts about overseas work/volunteering and I'm wondering if anyone can give me feedback/tips on how you do it? 

I haven't started nursing school yet but will be entering an accelerated BSN program. On the weekends I currently work as a CNA. I would love to do missionary nursing or medical mission trips for longer. I recently did a non-medical mission trip that was short term so saving for it wasn't too difficult. I read somewhere that certain companies frown upon fundraising and the traveler has to find their own way. How do you do that if you sign up for a 1 yr+ commitment? For those of you that have done that, do you move.out of your place, put stuff in storage, and quit your stateside job then look for another one a year later? I guess I'm wondering how to navigate the awkward talk with your boss that you're quitting or would like a year off and can they hold your spot for when you return. Have any of you experienced difficulty getting a new job upon returning because of too much overseas volunteering makes for a wonky resume of quitting jobs? 

Ideally I'd like to be employed by an organization like Cure, Red Cross, or Samaritan's Purse and then be sent somewhere occasionally or during disasters but it's doesn't seem like those organizations have stateside nursing jobs. And some paid overseas organizations like Peace Corps seem to be more health education related versus hands on nursing. 

Thanks for reading. I'd appreciate any insight!