UP

The first hit is called a "serve."  You hold the ball in your left hand if you are right handed.  Put the ball in your right hand if you are left handed.  Take one step forward and move your hand away from your body.  Pull your other hand back while moving your hand forward.  Then hit the ball with with your wrist.

The second hit is called a "bump."  When the ball is coming to you, clasp your fingers together and hit the ball with both wrists.

The third hit is called a "set."  Put your hands above your head and hit the ball with your palms.

The hardest but best to use is called the "spike."  When it comes over the net, jump up and whack it down with your right/left hand.  Use right if you are right handed, use left if your are left handed.