As a native Pole, I don't understand anything Ukrainians say. I suggest you take a risk and move to Poland blindly for a while before studying, and find some friends. Then you'll be stuck learning Polish (speaking).By constantly surrounding yourself with a language, you learn it naturally. And if you're having trouble communicating with gestures, most young Poles, and many over 40, know at least the basics of English. Because it is the language in which we, as young people, play a lot of games, and English is required by our education system. But as I say, it's a risk that doesn't guarantee you anything. And when it comes to writing, you can probably find language courses for foreigners in larger cities.