Be sure to wear knee and elbow pads when you're playing on a hard court to protect you when you dive for the ball. When you go up for the ball, try landing on the balls of your feet with your knees bent and your hips lowered a little. Also, warm up and stretch before you play, and take off any jewelry.
Communicate with your teammates while you're playing to keep from running into each other. Make sure everyone on the team knows to "call" the ball by saying "got it" or "mine" if they plan to go for it.
If you're playing outside, find a soft court made of sand or grass, and clean up any sharp objects that you see. Be sure that there aren't any trees or basketball hoops in your way. And, wear sunscreen and always drink plenty of water. If you're playing inside, the court should be made of wood.
If your volleyball net is held up by wires, make sure they are covered with soft materials. That way you won't get hurt if you accidentally jump or run into the net.