Hello. I do not understand this engine is paid or not? I want to open a question and answer site
Discourse itself is free, and the code is open source. But hosting it on the cloud costs money. In order to run your Discourse instance(Self-hosted), you need to either rent a server or buy one(Very expensive). Does this answer your question?
If you use the standard install guide provided by Discourse it will only cost you $5 a month and is super simple to set up if you need help I’m more then willing to
Can I make a website in Russian? Who can help? write me in Skype live:robdomdom
Yes. You can see try.discourse.org where you can see the Russian translation in your profile where you can select languages.
Also, keep in mind that Discourse is not a Q&A software but a discussion software.
Those have some similarities but are very different beasts.