As the the others have said, if you don't have a iPad that is cellular ready then it won't be able to function as a GPS navigator on the road as it doesn't have a GPS Chip installed. It does have "wifi assisted gps" which can find your position within a few miles using Wifi "triangulation", but this is not really of any use in a moving vehicle.
If you are planning to get an iPad I would highly recommend spending the extra $100 or so and getting the cellular version even if you don't plan on activating a data plan. But data plans start out as low as $20 for 1GB of usage.
Apple Maps is getting better but was the laugh of the mapping programs when first came out with taking people to wrong place,etc. If you have used a Garmin Street Maps GPS before and like it the App Store has a fantastic "Garmin Navigator" for iPad/ iPhone. It is totally self contained, meaning you download about a 2.5GB app and then it works just like your store bought Garmin GPS and does not rely on any kind of wifi or cellular data use once installed. I think the basic app is around $50 and if you get all the "extras" like traffic data, etc...then it will run about $100 I believe. I have used it on my iPads and iPhones for the past 3 years or so. It is like having a 10" GPS screen. Ram Mount and others have dash mounts for the iPad and iPad mini that will put that huge very easy to see screen up on the dash.
Another inexpensive option if you have a hot spot on your phone is to purchase something like a "Hisense Sero 7Pro" Android tablet at Walmart. They are around $130 and feature both blue tooth connectivity and an actual GPS chip. This would allow you to used the very good Free Google Maps application. The downfall to google maps over the iPad with The Garmin app is that if you get into a location that there is no cell data for your phones hotspot then the program has no way to update the Maps as you are driving. Again with the Garmin app on the iPad or iPhone the entire mapping data is on the device so it is fast to load and works even when out of cellular data in the middle of nowhere.
Sorry for the long reply...I am sort of a techno geek, so to speak...
I have attached a couple of screen shots of the app on the iPad...