Practice flying. Get used to flying your kite on land. You should be in control of the kite at all times and know what to do if things go wrong. Practice flying the kite at the edge of the wind window, 11 o'clock for left and 1 o'clock for right first. Then learn to do figures of 8 to pull you in a straight line. Once you've got this sorted, you can move onto the water.
Learn about body dragging. You'll need to know how to do this if you have to retrieve your board whilst in the water. Whilst the kite is in the air, practice dragging yourself up and down the wind direction through the water. This is essential to safety so make sure you are very comfortable with it before progressing further.
Get on your board. Whilst your kite is in the air, sit back in the water supported by your harness. Then practice putting your feet onto the board and just simply float there getting used to the feeling. Finally, pull yourself up into a standing position being careful not to over rotate or you'll fall forwards.
Learn how to change direction. To change direction is simple. Just push the bar forward and bring the kite right above your head. This will slow you down and allow you to move the kite to the other side of the wind window to start you off in the opposite to direction.