Especially what do Polish girls like to do on the first date.So would like to know some DO's and DONT's
I am no expert on women or Polish women, but there probably isn't a big difference, maybe there might be some cultural differences.
You are not a Polish man though so maybe it wouldn't be in your best interest to copy them or treat her like she would expect a Polish man to treat her. Maybe you can adopt some of their habits and add a few of your own. There may be a thing about holding her coat for her so that she can put her arms into it, her friends or family may think badly of you if you don't do this, if she doesn't like it maybe you could just do it in front of her family and friends so that they won't give you or her a hard time about it.She may expect something better or different as you are not Polish.
Who knows, this is a judgement thing for you to sort out.
At the end of the day you should treat her as good as you can and care for her like you love her until you do. Use your own judgement, but don't do stuff without good reason, don't follow advise blindly.