The bowler's is to bowl the ball to the batter aimed at the wickets. To be a bowler you need to learn the correct way of bowling. To bowl the ball you hold the ball over the crease like bunny ears but with your thumb sticking out. Batting is pretty simple all you really have to do is block the ball if it's a good one on the wickets, if it's a bad ball you try to smash it.
If you know that the person batting will hit the ball pretty hard, you should probably get ready with your eyes on the ball or get under it so that you make it easier for yourself to catch the ball.