Is It Better To Use Xamarin For Android Or Android Studio?

Do you want to develop a cross platform app: if yes use xamarin if not use android studio

https://www.quora.com/Which-is-better-for-Android-Android-Studio-or-Xamarin-if-I-want-to-develop-only-Android-apps-Will-developing-using-Xamarin-be-entirely-free-What-are-the-pros-and-cons-of-each

I would go with Android Studio. Android uses Java and XML which are not platform dependant (can be used on any platform). Android Studio is free and well supported. Also it is the official app developing tool for Android. It is the old maxim: " If it is not broke don't try to fix it".

Depends on whether you prefer C# or Java.

You can also use cordova if you want to use html/js.