change the language of my main page
Check if you have activated these modules.
Views translation and  Block languages (i18n_block).

Then You need to change those blocks language settings in configuration. follow this: https://www.drupal.org/taxonomy/term/39286

tick "make this block translatable" and select the languages.
it will allow you to translate a block in to a language you want. you might need to create separate blocks for each language.

In a View check if "Field Language" selected as "Current user's language" in Advanced area. 

also use a filter for the view "Content: Language (= Current user's language)"

This will populate the content by detecting the users selected language.
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