How can I add support of Russian language ?
All russian names of files shows me ????????? and etc.

At which system?
What distro you are use?

Для начала надо проверить что говорит locale. При необходимости настроить локаль системы. При использовании юникода все должно быть нормально.
И посмотреть с какими параметрами смонитрована ФС, на которой не видно имен в кириллице.

I use Debian Jessie with GPU driver, WiringOP, Wifi, Retroarch etc preinstalled ( http://www.orangepi.org/orangepibbsen/forum.php?mod=viewthread&tid=867&extra=page%3D1 ).

I know many people choose foreign languages in different apps or platforms or even try to communicate with customer support in a foreign language just to improve their skills. Is this effective? I’m currently learning Spanish using Promova https://promova.com/app/spanish-language-learning-app, which offers a very functional and user-friendly app. I’ve always wanted to learn Spanish, but finding the right tutor is a challenge. Using an app is the best option to start with.