Prerequisites for getting started with android app development

Hello

I have experience with Android app development. I want to develop an android application which can communicate to some

SAP back-end. I don't have any knowledge about SAP. I went through SAP website and found a lot of things and finally I am

confused where to start and what are the prerequisites for beginning android app development.

By prerequisites I mean what are the components I need to setup (like backend SAP server, SUP/NetWeaver Gateway)

before starting app development.

Any guidance in this will be very helpful.