The Hillary theme features an Instagram feed in the top section of the footer. This utilizes a free plugin called SmashBalloon, but you of course can add it through other third-party functions as well.
Until your Instagram is connected, there are some placeholder images that you’ll want to remove before publishing your site. You can remove these by navigating to WordPress Dashboard>Appearance>Customize>Footer>Widget 2. Simply Delete the placeholder images by clicking the gear icon, then deleting that gallery block in the left sidebar.
To connect your Instagram feed, navigate to WordPress Dashboard>Instagram>Setup and follow the setup wizard.