Back up your iPad by backing up to the cloud. Go to Settings - iCloud and then turn on all the apps that you want to back up.

Tap on 'Storage & Backup


This will tell you what your total storage is and how much is available.

You can change your storage plan by purchasing more space

Ensure that iCloud Backup is on.

Check when the last Backup happened. Click on Back Up Now if you need to back up