Law / Citizenship by descent: don't know details of grandparents' American citizenship [8]

citizenship/polish passport/relatives

Hello! My grandmother never got US citizenship but my grandfather did. My grandmother, Katarzyna Bartyzel,from Boknia, and grandfather, Jan Jacob Imiolek, from Jauwuf(?). I would like to get Polish citizenship or a passport and also find both sides of my family there.

Where to begin? Thank you!