You can display a footer navigation by following this two simple steps:
Create the navigation
Go to Layout > Click on 'Navigation'.
You can use the already existing Footer navigation. Add the appropriate links to it.
If your theme allows you to add additional navigation in the footer, add another navigation.
Link the appropriate navigation in the theme settings
Go to 'Layout' > Click on 'Theme settings'.
From the right menu, select 'Footer'.
Make sure the option 'Show first menu' is selected, and from the drop-down list for the second menu, select which navigation to display.