I enjoy watching Tennis, even if I don't much understand the scoring
I don't know much about tennis other than they use a racket
And a ball, don't forget a ball haha. Oh and they have a net too, can't play without a net.
I know it is an Olympic sport and many people like to watch it!
Are you sure it is an Olympic sport? I don't remember seeing it in the Olympics.
It is an Olympic sport, and it is played at all levels of society and all ages. 
Oh that is cool, well not all ages. You aren't going to have a 2 year old tennis player.
Interestingly enough, it can actually be played by anyone who can hold a racket, even crippled people.