Q: how do I turn off  airplane mode

Settings > Airplane Mode 'off' - it's the first option on the Settings screen.

Or if you have iOS 7 on your iPad you can also do it via Control Centre - swipe up from the bottom edge of your iPad to open Control Centre

Turn off Aeroplane Mode (tap to enlarge image)

if you have the newer IOS you can swipe up for the controls and there will be an icon for an airplane and see:

http://support.apple.com/kb/HT5463 for more info