This link is a good example of how to add GA to you wordpress site:
1. Create a google analytics account and get the tracking code
2. Add the Google Analytics Code to Your WordPress Theme
Copy the tracking code. Go to your WordPress Admin and then Appearance > Editor.
Open your theme’s header.php file and directory underneath the < body > tag, paste the tracking code. Click “Update File”.
3. Go to your google analytics account and check it s working ok.