Sadly, if you are using a Free WordPress Account, you cannot reap the benefits of Google Analytics. The only way to do so is by upgrading to a WordPress Business Account Google, as scene below.
If you have already or plan to upgrade, adding google analytics to your wordpress site is actually very simple. The most basic way will be shown below.
Step 1: Visit Google Analytics and Log in
Step 2: Click on the Admin Tap
In the Property drop down menu, click create new property
Enter your website information and Click Get Tracking ID
Step 4: Copy Tracking ID
Step 5: Paste into Page “text”