You'll want to upgrade your site's Google Universal Analytics script to use Google's latest script. This should probably be done regardless to whether or not you use Google Ecommerce tracking.
You can do this by logging in as a superuser, and then navigating to the Host > Configuration Page.
Select the SiteAnalytics configuration file.
Copy the analtytics script from the Google link above, and then paste into the analytics file. Be sure to replace the token for your analytics ID. Save your changes.
You're now ready to do anything else related to Google Analytics, whether it's a Hotcakes feature or not.
If you want to enable Google Analytics Ecommerce. go to the Analytics page in the Hotcakes Administration. Enter the information as you desire, then save your changes.
By the way, the CMS has another place that you may want to ensure has the correct GA tracking code too. You'll find it in the Admin menu.