Step 1: Go to https://analytics.google.com to setup an account.
Step 2: You'll see a screen that displays your codes.
Tracking Code = Google Analytics Code in Brivity
Step 3: Open the site builder and click the pencil icon.
Step 4: Click on the hamburger menu in the upper-corner and click Site Settings.
Step 5: Copy/paste the Google Analytics Code.
Save your changes in the site settings. Then save and publish your site.
Learn more about Google Analytics here.