1. just wondering that where we can enjoy rock climbing in Poland?
I believe that [en.wikipedia.org/wiki/Jura_Krakowsko-Czestochowska]Jura Krakowsko-Częstochowska] is the most common place for rock climbing.
2. Actually I have some research of rock climbing. I need used rock climbing rope.
I have nothing to do with this sport (so I know aboslutely nothing on climbing) but if you need some used gears try to buy it on polish equivalent of ebay - allegro.pl
Also I believe that there are places you can just borrow such equipment.
Here you have pointed some more precised places in Jura K-Cz but the site is in polish:
something in english here: