nezecus
Good to know you’re loving it as well 🙂
If you can’t see the menus on the site, it usually means someone removed them from the menus, try checking the Menus option under the Appearance settings in the WordPress Dashboard of your site. Here’s some more info you can go through if want to know more about menus:
https://codex.wordpress.org/Appearance_Menus_Screen
About setting up the footer, you can do that by creating a child theme of the Nimble theme and modifying its footer template. Here’s some good read on what child themes are, how to create them and get your customisation working
https://codex.wordpress.org/Child_Themes