The iWork for iOS apps are free for anyone who has activated an iOS device for the first time since September 1, 2013. If your iOS device is older than that you will have to purchase the apps or a new device. Restoring & setting up as new will not get you the apps for free.
If your iOS device was activated for the first time after September 1, go to the App Store on your iPad which should open to Featured. If not, tap on Featured at the lower left of the screen & scroll down to Collections & tap on New to the App Store? then scroll down to Apps Made by Apple & tap. You should now see the iWork & iLife apps as "FREE."