Rustic: Footer Widgets
Watch this video FIRST:
The Before Footer widget area, as mentioned in the video, is located under Appearance > Widgets. This is the short code you add to a Custom HTML widget to have your Instagram feed display:
Make sure you've already connected your Instagram feed by clicking on Instagram in your Dashboard. This is the Instagram Feed plugin by Smash Balloon that you've already installed with your theme.
To turn on your social icons in the footer, go to Appearance > Customize > Theme Settings > Footer and make sure that checkbox is checked.
Note: You need to have already added your social links by setting up Simple Social Icons in the Social Media widget area.