Generally most young people in Lodz under 30 speak a few words of English (in may cases more than a few words) and the traders that do business are generally accommodating to the many different languages. Don't expect anyone over 40-50 to be either enthusiastic about your presence or to speak anything other than Polish, again there are exceptions. The school is there to help you get your licence and they do everything to support you with your professional aims. If they had to concentrate on all other aspects concerning your life outside the school then it would dilute their available support. You need to show initiative and organisational skills, after all you want to become a professional pilot operating worldwide, a role that requires a high degree of autonomy.
Edit: Before you go a nice touch might be to do a few online Polish lessons, just making the effort to speak the language goes down very well with the locals.