Visit https://firebase.google.com/ and click “Go to console” from top right corner, which will redirect you to Google Login. Use your gmail credentials to login to Firebase console.
From opened Firebase console, click on “Add Project” , on the next page, Enter the project name and click “Continue”
On the next page, Google Analytics is enabled by default, keep it enabled and click “Continue”
On the next page, you would be asked to select your google analytics account. If you have already registered your website ( if you have) for the same domain for which you are trying to develop and android app, then you can select that Google Analytics account or click on “Create New”
Once you accept the terms and conditions, when you create new Google Analytics account, your Firebase project will get created.