Buy An Iphone

There is no such thing as a global phone. You will receive the iPhone model Apple sells in Poland, which should be pretty much the same as the iPhone sold in all European Union, countries. It will lack the mmWave band which is included in iPhone's sold in the US. But that won't be an issue as Europe doesn't use mmWave 5G services.

No.

you will get the same phone as if you purchase it a store in poland