Before we dive into ABAP you first need to setup your development environment. Currently the primary development environment for ABAP is the ABAP Development Tools (ADT) together with SAP Build.
To install ADT you can find detailed instructions in this tutorial ABAP Install ADT Tutorial.
Quick steps as a summary:
Download the Eclipse IDE and add the ABAP Development Tools (ADT) Plugin.
Open the Eclipse download page to download the appropriate (usually latest) Eclipse version. Open the Eclipse download page to download the appropriate (usually latest) Eclipse IDE For Java Devlopers version.
Once installed Eclipse add the ABAP Development tools:
On a regular basis there will be updates to Eclipse and the ADT. It’s important to keep your installation up-to-date using the Eclipse build-in updater.
Great!
Now you are all set to make your first steps in the ADT based ABAP World. In the next chapter you learn how to configure the ADT to be used within the SAP Build environment.