Register Google Developers Console APIs

1- Google Developers API

You need to have a Gmail account, please sign into gmail and then switch to the URL:
You need to create a Project on  Google Developers Console.
Note: You can create one or more Project for different purposes.
Project name should be named after your company, here I named MyApp.
Your project is created.

2- Register Google Map API for Android

Firstly you need to choose the project, for example, I am standing in the MyApp project.
If APIs is not enabled,  you need to enable it:
Click on "Google Maps Android API".
Enable "Google Maps Android API".
Google Maps Android API is enabled, but you can't use it in your project until you create credentials. In that case you need to make a credentials.
Naming your Android API Key is "My Android API Key for Tutorial".
API Key is created.