1. Are you trying to update the iPad to the latest iOS version?
2. Are you trying to update your computer's operating system?
If you're trying to update your iPad, you can go to Settings - General - Software Update, and if there's an available update, you can select to update it, but you must be connected to a Wi-Fi Network. Alternatively, you can connect your iPad to your computer, initiate the computer's iTunes app (preferably the latest version) and then when iTunes recognizes the iPad, it may also alert you to an iOS update. If so, select to update it. In any case, please make a backup prior to updating your device.
If you're referring to something else, please provide more details. Thanks.