How can you write an online game for Android?

Question

Java

Good day. Recently I have been studying Java Core, later I want to switch to android application development and now I have an idea to create an online RPG game for mobile phones. (at least for Android)
The question is what technologies should be studied to create such online games, Will Java work with Android Studio or libGDX, or will I have to learn C# with Unity?

Answer 1

You can use libGDX, you can use units, you can use any other framework for games.
On pure java - I do not advise.

Answer 2

Learn C# and Unity right away.
There is cross-platform compilation for all known platforms (including the Web) and game consoles.

Answer 3

Unity or Unreal. Here I would chat with the developers who did something similar and what they encountered. The ideal is to visit the WhiteNight or Devgamm game show and discuss these points there.
By the way, there is more Unity, but Unreal is also there.