You hit the ball over the net — like, you actually need to hit it over the net to beat your enemy. To do so, hold the racket in a way that there's a V shape between your thumb and index finger, in a hammer-like way.

Then after all that, you're still not finished. You need to stand in a way that you are sideways. If the ball is left of you, turn 90 degrees clockwise. If the ball is right of you, turn 90 degrees anti-clockwise.