what does "home is where you hang your hat"mean?
“Some house,” Corbett commented. “I’ve seen it from the outside, and it sure makes a statement. Makes one on the inside, too.”
“Home’s where you hang your hat. If you’ve got one. We might as well sit down.”
He took an internal scan of himself as he did. His palms weren’t damp, his heart wasn’t racing, his throat wasn’t dry. All good signs.
And still, looking into that bulldog set of Wolfe’s face, those hard, flat brown eyes kept him wary.2.does "if you've got one"= if you got home?

Question

what does "home is where you hang your hat"mean?
“Some house,” Corbett commented. “I’ve seen it from the outside, and it sure makes a statement. Makes one on the inside, too.” 
“Home’s where you hang your hat. If you’ve got one. We might as well sit down.” 
He took an internal scan of himself as he did. His palms weren’t damp, his heart wasn’t racing, his throat wasn’t dry. All good signs. 
And still, looking into that bulldog set of Wolfe’s face, those hard, flat brown eyes kept him wary.2.does "if you've got one"= if you got home?

Answer

It most likely means "Home is where you are most comfortable" or "Everyone comes home at the end of the day".

"If you've got one" is referring to the hat: "If you have a hat, that is," has the same meaning.

I hope that this helped :)