Child theme translation

Hi,

I have a problem translating my child theme (I’m newbie with translating). I translated the embr.pot file with POEDIT and saved the file as “fi.po” and “fi.mo”.
I also took a copy of the .po and changed it to “fi.pot”.

To which folder should I put these .po, .mo and .pot files? Do I need them all?

How should I edit the functions.php? I checked the wp-config.php file and it was already using “fi” as a language. Am I missing something?

Help me! Thanks!