Answer 1

No, this gives the basics of the Java language but there are many more elements involved getting it to talk to other technologies (e.g. database system). Best thing to do would be to check out some Android tutorials (Google themselves have some excellent ones) and put your knowledge of Java to good use in an actual project. You will learn about the Android framework and how your Java code interacts with that to produce your app.

It's all steps in the right direction, learn the basics, use in a project, learn new things and repeat