I'm an Idaho native. I grew up in Twin Falls, which is in the south central part of the state. Mountain Home is 1.5 hours from Twin and about 30 mins or so from Boise.
The geography will be really different for you coming from Hawaii. It's hot and arrid. It is a desert,not with cactus, but with sagebrush. It gets hot during the day in the summer, but the nice thing about the high mountain desert is it does cool off at night. But, you'll be just an hour or so(more like 1.5)to the mountains..and that's a good thing!
Shopping wise, anything you might need you can find in Boise. All the major retail chains are there. There is a food co-op..but it's not a true co-op. It's expensive yuppie marketing driven. There are other health food stores around.
Idaho is conservative.
Hmmm, what else can I tell you? I've not lived in Mountain Home..but have lived in Boise for a number of years. I attended college there, and then lived there after graduation.
I love my home state very much!