We need to support
First You need to install the Language packs for the extra language. I.E. if your base load is in English then you need the French Language pack to install on you SharePoint farm.
you can get all LPs overe here: https://technet.microsoft.com/en-us/library/ff463597.aspx
I think you need to plan the multilingual site collection.
The multilingual user interface (MUI) feature enables users to display the user interface of a SharePoint 2013 or SharePoint Online site in the language they prefer, instead of the default language that was selected when the site was created.
Please check this technet for complete details:
Another option is you can create the a site collection for each language. it is easy but required extra work,
This option creates a site in which the site user interface appears in the language that was selected when the site was created. For example, if the English version of SharePoint was installed, but French is selected when the site is created, the site user interface will appear in French.
You can have a web application say
and create two different site collection
and for the content, you can have a configure an
event receiver which gets triggered whenever user adds a page to en site and adds that to the pages of fr site collection after changing values to french using some config file.
For example if it has date month year etc, french translations for those can be save in a filed and they can be changed accordingly
If you want to add one more round of validation, you can have the pages saved into fr site collection in draft mode, and the site collection admin of fr can change the content to french content and publish it for