Adding custom nav menu to individual pages

I am trying to add a custom nav menu to each page except the landing page. The idea is that half the pages will be in English and the other half in Portuguese. So I need one nav menu in English and the other in Portuguese, and then will place them on the appropriate pages. I tried to do this by adding a custom sidebar but it looks like this theme doesn’t support certain widgets on individual pages? Does anyone know how I might achieve the nav menus I need?

The page I need help with: [log in to see the link]