Edit links in footer
It's pretty much impossible to be sure just by looking at the site. But there's a good chance the links are coded into the templates.

Again, the exact template could be anywhere. It's common to create a partial include it in a layout template but could equally just be within the layout template itself.

You don't say if this is Craft 2 or Craft 3 but you'll need to look in either /craft/templates for Craft 2 or /templates for Craft 3

You may also find you have an add on such as NavEE or A&amp;M Nav installed. This allows the creation of navigation blocks which can be included in templates. So you might find the links in there.