I'm not the best at playing basketball..
Do you like to play basketball, though, even if you aren't great at it.  It is so good for exercise, and it has a limited amount of contact as well which makes it safer than some other sports.
That's true. Sports like football are really dangerous. So what is the main idea of basketball? 
Well, most of the time it is played 5 on 5, but if you don't have 10 players handy you can play with as few as two people, but the goal is to shoot a basketball through a hoop slightly larger than the ball.  It takes a good amount of skill, but still fun even if you aren't too good at it.
Cool! Sounds like you need some coordination. Is it popular in other countries? 
It is!  It was invented in 1891, and has grown in popularity over the years.  It has really caught hold in Europe, China, Canada, and other countries.  It is actually one of the more popular sports in the world.
Wow.. I really had no clue! I thought it was just an American thing. Is it in the Olympics?
It is in the Olympics.  The United States normally puts together a phenomenal teams, but more and more other countries are competing very hard for the Gold medal.  They score their hundreds of points 2 or 3 at a time.