First of all, the main thing is to locate a solicitor fluent in your native language. Probably any number of competent lawyers in a big city such as Wroclaw, Warszawa, Krakow etc. will know excellent English. On the other hand, there are doubtless plenty who don't, therefore, I'd recommend (short of procuring such a person before coming to Poland) hiring a well-seasoned interpreter, recommended to you either through personal contacts or the local Polish Consulate in your country.
Merely my thoughts on the subject.