How to make my first android App from scratch ?

Android App 

Android is a mobile operating system based on a modified version of the Linux kernel and other open source software, designed primarily for touchscreen mobile devices such as smartphones and tablets. Android is developed by a consortium of developers known as the Open Handset Alliance and commercially sponsored by Google. It was unveiled in November 2007, with the first commercial Android device launched in September 2008.

1. Setup Development Environment : We use Android Studio as IDE i.e Integrated Development Environment. 
2. Start the Android Project 

3. Set up the Emulator.