In order to use GPS on an iPad it must be a WiFi+3G/4G model. This will work without any kind of Internet connection. All you need then is an app that will let you download maps for offline viewing. If you want to know much more than where you are in relation to the map, you'll need to download one of the many available GPS apps. There are many free and paid GPS apps in the AppStore. Some of them allow you to download the maps in order to navigate while offline.