Follow below mentioned steps to easily get Google API Key for Android:
Step 2 : If you have a Google account, login, else Signup
Step 3 : On Google APIs dashboard, click on dropdown menu

Step 4 : Click on New Project

Step 5 : Click on Create button
Step 6 : Click on Enable APIs and Services

Step 7 : Click on View All

Step 8 : As shown in the screenshot, you need to enable the highlighted APIs one by one by clicking on Enable button in the next window