Hello, are you a fan of the NBA? 
Not really, I don't know much about sports.
Oh okay I understand. The NBA is the National Basketball League. It is a professional basketball league for men in America that has 30 teams, and one of those teams is actually in Canada.. 
Only one for all of Canada? Do they have their own league?
National Basketball Association
The National Basketball Association (NBA) is a men's professional basketball league in North America, composed of 30 teams (29 in the United States and 1 in Canada). It is one of the four major professional sports leagues in the United States and Canada, and is widely considered to be the premier men's professional basketball league in the world. 
The league was founded in New York City on June 6, 1946, as the Basketball Association of America (BAA). It changed its
premier men's professional basketball league and one of the major professional sports leagues of North America. It contains 30 teams (29 teams in the U.S. and 1 in Canada) that play an 82-game season from October to June. After the regular season, eight teams from each conference compete in the playoffs for the Larry O'Brien Championship Trophy. The NBA get high ratings on television.
Race and ethnicity.
The composition of race and ethnicity in the National Basketball Association (NBA) has changed throughout the league's history.