it's very country

Connecticut is really nice. In the northern part. It's very country.

'It's very country' is a phrase used to describe something that has a rustic feel to it.

Notice the following:

1. I love your new kitchen table, it's very country.
   
2. The style of house I want is country.
   

things like that

So there's lots of trees and grass and things like that.

'Things like that' is a phrase used to describe a group of things that are all similar to something else. We use this when we don't want to list off all of our examples, but we want to give the listener the general idea.

Notice the following:

1. I like skiing, jogging and outdoor things like that.
   
2. Things like that are really hard to find .
   

how long

How long have you been in Japan?

'How long' is used to ask for what length of time something happened.

Notice the following:

1. How long do I need to cook the lasagne for?
2. How long have you been able to speak fluent German?
   

black belt

And do you have a black belt?

When you have a 'black belt' it means you have earned the highest award in a particular martial art.

Notice the following:

1. You don't want to start a fight with him, I have heard he has a black belt in karate.
   
2. I have my black belt exam next month.
   

practice

Do you practice karate in the United States?

Used like this, 'practice' karate is similar to 'do' karate.  'Practice' can also mean repeating the same actions many times with the intention of improving.

Notice the following:

1. I am not very good at singing and I need to practice.
   
2. He needs more practice if he is going to get his black belt.