You could try triple-clicking the home button and see if that turns it off, and if it does you can then change what a triple-click does via Settings > General > Accessibility > Triple-Click Home. If that doesn't turn it off then you need to tap a field to select it (it should then get a box around it) and double-tap it to type/activate it - so to type a number of your passcode you need to tap and then double-tap.
When you've entered your your code you can then either use the tap to select/double-tap to activate technique (with 3 fingered scrolling) to go into Settings > General > Accessibility and turn VoiceOver 'off'.
Or you can turn it off by connecting to your computer's iTunes : http://support.apple.com/kb/HT4064
The find my ipad alert has problems. when you play a sound to find the ipad it is impossible to get rid of the alert and the ipad screen is locked. you cannot turn the ipad off either. I finally found that by tapping and holding the OK while at the same time turning the ipad off that eventually it did turn off - not easy. Suggestion - do not use the find ipad app just to locate the ipad until Apple makes it easier to use.