If your application is going to have a big focus on Maps, and a lot of its functionality relies on displaying information inside them, I would recommend using Xamarin native to build that app, however, if you only need to use map slightly, to display some information here and there, but the main functionality of your app is something else, and pixel-perfect accuracy for the maps is not vital, there is a way of how to use Maps on a Xamarin Forms app.
In this post, I will focus on getting the maps ready on iOS, but keep in mind that the code used to display this will work on both iOS and Android (it's just that preparing the Android project to display maps will be covered later).