Law / Living in Poland for the purpose of studying entitles me to apply for Karta Stałego Pobytu (permanent card)? [5]

Merged: non EU citizen how can apply for karta pobytu?

Hi,
I am an non-EU citizen (Albanian) and i have a residence permission in Greece. I am going to visit Poland for erasmus program studies. As i know i can travel in Poland with Shengen visa for 90 days but the period i will be in poland is about 5 months (february-june). I asked in the polish embasy in greece for a visa and they said me that when i go in Poland i shoud ask for a visa in the polish authorities or something like that, so i guess that they meant Karta Pobytu. So i want to ask for any information that could help,such as the document required for application and so. Also, supposing that i will take the karta pobytu, can i visit greece for renewing my residence permission in Greece that expires in May, and then come back to Poland, is that legal? Will they allow me enter Poland again?

so, briefly my questions are:

documents required for karta pobytu (for studies)

I need a visa for at least 6 months, is that easy?

supposing that i will take the karta pobytu for 6 months can i cross the border(in this period of 6 months, or the period that visa allows me) and then enter again poland with the same karta pobytu?

Τhank you in advance!