I guess you're going to have mostly a mixture of English (not understanding Polish) and Polish (not understanding English) guests .....
It sounds a bit like my wedding, where my wife is Polish and I am of Polish parents but born in London, England.
We had the wedding in Poland, and for the reception we decided not to have the traditional English after dinner speeches from the best man, father of the bride and the groom; instead both my wife and I gave a speech with my wife doing the Polish version and I did the English.
Good luck with your wedding :o)