I setup Itunes to Home share but if i close itunes noting shows up on the Apple TV
do I have to leave itunes opened? or is there something wrong?
Yes, you will need to leave iTunes running so that it can access the Home Share that you have setup.
You can get itunes in the cloud if you subscribe to iTunes match in which case your apple TV can stream your music direct from the cloud without your iTunes being open. It is a subscription service.
Retrieving data ...