I just had a quick read and in general, as long as your UAV is < 25 kilos, you are flying in line of sight and only for recreation - you are fine.
There are some restrictions in terms of aerial spaces, i.e. there are some air space categories only in which you can fly but too many details.
Just use common sense, stay away from military air space, airport air space, don't fly over cities or dense metropolitan areas - the same as you would in USA, UK or wherever you're from.
Where in Poland do you plan flying? Any particular places you want to film?