Translating Child Theme

Hello

I am currently creating website http://www.riesky.virpo.sk and I am using theme called hueman…
To be able to update the theme and not to lose all changes I made, I have created child teme called hueman_riesky
Everything works fine, but I am having problems with translation

There is a folder called Languages inside both theme and child theme
They have file en_US.mo and .po and I created sk_SK.mo and .po files with translation

But how do I make it work? Where do I point to that sk_SK file? My backend and many plugins are translated just fine, because they were translate-ready I guess, so how do I make this translation work?

I read something about adding some hook into functions.php, but into which theme? Original one or child theme? Because child theme has no functions.php
Also the sk_SK should be located in child theme or parent theme or both?

There are many things I am no tsure about and that are not clear to me, so I am looking for complete solution of this problem 🙂