Salut,
wiki Linux Mint a écrit :Menu>Control Center>Administration>Language Support.
The Language Support feature is an additional utility added to the Mint by Clem).
Here you can uncheck all languages that you don't need and leave yours (and English (en) perhaps. This will empty some space in your hard disc and also you will not be reminded later to update any languages you might not need, except your language and English. (I found out that you don't have to download the language packs that are listed down below if you do this! But it is wise to check the repository to see if they have been installed).
Now,at the bottom, in the Language Support there is a window which says Default Language for new user accounts and Login. You have now two options there, English or your language. Make your selection here!
When you reboot your PC, you will have all of the menus in your language.
After installation, manually adding some language extras from the Repositories, one has a perfect translation for his language. The installation of the following language packs from the Repositories, can also change the language in any Mint version, after installation to your hard disc.
Voilà pour la langue ( non , je ne ferai point de RTFM

)
Ensuite pour le routeur, tout dépend de tes précision...
C'est sur cet ordinateur qu'est branché le routeur ?
Tu veut te connecté via le wifi vers ce routeur ?