The Happy School Days theme displays three footer widgets above the secondary navigation at the bottom of the site. To add content to each of these widgets, go to Dashboard > Appearance > Widgets > Footer One (and then Footer Two and Footer Three), drag your desired widgets into these locations.
Note that you will need to add content into Footer One before the content in Footers Two and Three will be visible on your site. Don't forget to click Save to save the settings for each widget.