[Résolu] Setup is a nightmare

Background of the issue:
I am trying to translate the last bits on my site, like the footer, using an article I was pointed to earlier today. The link to a page where the issue can be seen is lien caché.

Symptoms:
I don't understand the contents of the article and cannot resolve my problem. Additionally, some of my pages are formatted differently on translated pages. Like lien caché
I also have dublets on pages under main language, see image

Questions:
How can I understand and use the article to translate the footer?
Why are some pages formatted differently on translated pages?