Learn how to configure the theme footer here. In your control panel, go to Storefront > Themes, and click the blue "Customize" button to launch Theme Editor. In the left hand column of the Theme Editor, click the panel labelled 'Footer'
Social Media Icons
Check this option to show social links in your store footer. Note that you must configure these in your store Control Panel before they show in the store.
Check the relevant boxes to show brands and copyright notices in the footer.
Uncheck these boxes to hide the "powered by" and "designed by" credits.