One of the basic things which are traditional for Poland is a rule for men to bring a bouquet on a date. Women love flowers, at least most of them do, so that will be a nice gesture to do if you want to show your romantic feelings and serious intentions. But you should remember about the colour: bringing yellow flowers might be considered as the sign of envy, jealousy and insincerity.
Another important thing to remember is to be on time - Polish people are usually punctual and strongly dislike people who don’t respect their time and come later. If you have some unexpected troubles and can’t be on time, it's always better to predict a person you’re going on a date with a call or a text message, or you most likely will see your date’s back.
While having dinner in a restaurant, try to mirror a person you’re on a date with. If your partner doesn’t order any alcohol or food you shouldn’t do that either - it’s considered rude to eat or drink while your partner doesn’t do the same. Of course, it doesn’t mean that you should order the same amount of everything in a restaurant, but at least try to copy some things your partner does.