One of the challenges on shifting and venturing to another programming language or platform is having to figure out how to setup the right environment and tools needed for that language or platform.
In Android, the people in Google made this task the least painstakingly as possible . To get started developing in Android, you will only need to download the ADT (Android Developer Tools) Bundle. You can download this from http://developer.android.com/sdk/index.html#download
This bundle includes the following:
an integrated development environment used for Android development. Because Eclipse is also written in Java, you can install it on a PC, a Mac, or a Linux computer. The Eclipse user interface follows the “native look-and-feel” of your machine, so your screen may not look exactly like the screenshot below:
Android Developer Tools
a plug-in for Eclipse. As of this writing (July 2014) , version of ADT (Android Developer Tools) is 23.0.2 You should make sure
you have that version or higher.
the latest version of the Android SDK tools and Android platform-tools for debugging and testing your apps, a system image for the Android emulator lets you create and test your apps on different virtual devices
After downloading, you just need to extract it to your local drive and run the eclipse application executable file under the bundle and eclipse folder.
The only extra effort you need to do aside from the above is if your Java Runtime Environment version installed in your local machine is not compatible with the minimum requirement of the Android SDK. In this case, you only need to upgrade or install your Java Runtime Environment version to the latest one (check https://www.java.com/en/download/).
Next stop in this journey is learn android development