Choose the amount of points to beat your opponent! It is win by 2, meaning if you chose a 10-point match, and the score is 9-9 you play till 11. Also, choose your level, opponent and surface. Use the arrow keys to move or WASD to move. Move the player to the ball to hit it. The score is at the bottom left of the screen. Make sure to check the score all the time. You are the person at the bottom of the screen. Click the green flag to start the game.
I recommend level "Easy" if it's your first match.