Use correct dribbling posture. Your knees should be shoulder-width and you should be on your feet ready to move around. Don't stand with your knees locked. When you dribble, bounce the ball no higher than your waist. In a defensive crouch, the ball should come no higher than your mid-thigh.
Learn to dribble. Do as much as you can starting out, you'll need to start getting a feel for how the ball moves and responds to the force you put on it. It's also a good idea to exercise with each hand by itself to get comfortable going to the right and to the left. Alternate bouncing it quite hard and quite softly.