Dear Friend
Thanks for your letter. I am glad that you are going to Poland for a weeding. I hope that we will meet.
Polish weeding are really official so you should wear a suit. Usually the wedding starts with the bride and groom's first dance. When they finish people sit down at the table. After meals and toasts people are starting to dance. You will see it will be a good time. You will not be bored. Remeber to buy a gift for the bride and groom.
Let me know when you come to Poland exactly. We are in touch.
Take care.