Hello, I'm from Russia.
So, Russian is my native, so we can train it a lot.
English is my first foreign language. I study it for many years, but the result was quite low. But I find some good methods for mastering it and I can help you to do the same. I can share methods for learning words and to master grammar (to speak fluently).
Now my Japanese is low (about N5), so most likely I can't explain you topics in in, so you should understand a little Russian or English to make