Homosexuality is legal in Poland. However, the ruling Law & Justice (PiS) party is very anti-LGBT+ in its policies, reflecting the generally conservative, highly religious nature of many Poles. This said, in the major cities such as Warsaw, Kraków and Gdańsk, you'll encounter a much more liberal attitude.
All up this means the Polish LGBT+ scene is fairly discreet. Warsaw and Kraków are the best places to find bars, clubs and gay-friendly accommodation, and Sopot is noted as gay-friendly compared to the rest of Poland. The best sources of information are the Warsaw and Kraków city guides on www.queerintheworld.com, and www.queer.pl (in Polish only).