If you get a new iPad or experience serious issues you may have to restore your device from a backup. It can take some time but is usually easy to do. This is how you start restoring your iPad from an iCloud backup:
Go to Settings > General > Reset > Erase All Content and Settings.
Enter your passcode and follow the instructions.
This will erase everything on your iPad and let you set it up as if it was new. In the process you will be asked if you want to set it up as a new device or restore it from a backup.
If you choose to restore from an iCloud backup you will be able to choose between your available backups. Once you have chosen a backup, the data will be copied to your device. This may take a long time depending on how many apps you have installed, how much data you have stored and the speed of your internet connection.