There are two ways to translate your site. You can use the included .PO/.MO files in the lang folder . Or use any translation plugin such as WPML. Theme is compatible with WPML.
If you want to use the included pot files, then keep reading the necessary steps to take:
1-Find the pot files inside the \languages folder. Translate every string in it using a normal text editor or the PoEditor.
2-You can add more strings if you do not find them originally in the file. Save it as your country’s language code. Example, for french save it as fr_FR.po. (Find here a full list of other countries codes ) Upload the edited file in the “languages” folder.
3-Now we need to make the WordPress know that there is another language available. Add this line in your wp-config.php file:
define( 'WPLANG', 'fr_FR' );
4-Go to Settings > General > Site Language and select this file from the drop-down list.
So the site will use this file’s strings instead of the defaults. Keep a copy of the pot file in your computer to replace in case of future theme updates.
A live preview of this process can be found here: https://youtu.be/1xqcxncNmT0
Another useful article can be found here: http://codeless.co/5-steps-to-translate-a-wordpress-theme/
Let me know how it goes.