How do I turn off the music on my iPad?

Either go into the Music app and tap the pause button at the top left, or double-click the home button to open the taskbar at the bottom of the screen, slide that bar to the right, and press the pause button there (and then press the home button to close the taskbar).

If you haven't already got a copy then you can download a copy of the iPad manual from here http://support.apple.com/manuals/#ipad