Army National Guard and Air National Guard Questions

So I am seeking some guidance from of the National Guard side of the house. My ETS is in Jun 2017 a little ways out. But I am ready to leave Active.

I just have some questions and wondering if the more knowledgable SM could shed some light. I know I still need to talk to a recruiter but not ready for that yet.

I have been told that most people want to get on Active National Guard. Not sure how that happens or when you become available to do that.

I am going back to Washington State. I know I want to go National Guard versus Reserves.

Can you go from Army to Air Force? Would I have to do some type of training agian?

I know you can get Tri-Care but you have to pay for it correct unlike Active?

Sorry if these have been asked elsewhere, just looking for guidance from my fellow SM's.