Replacing the MainPage from App.xaml.cs
Here is the Complete Xamarin Developer Course: iOS And Android: https://www.udemy.com/complete-xamari...
Take the free course here on YouTube to learn the basics of Xamarin.Forms development, and take that full course (for $9.99 down from 199.99) to get into de depths of the Xamarin ecosystem.
Use a different page as the MainPage for the App class in Xamarin Forms