I'd like to know about the And Engine.

I developed a game app this time, and I learned that I can use And Engine by applying it to Android Studio, so I want to study And Engine, so I'll ask you a question.

First, I want to know what the And engine is.

Second, I'd like to get recommendations for related sites that help And Engine.

Third, is it possible if And engine self-taught?(If you have a relationship)

Please ask me questions.