What is a gambling shop
He means a betting shop.
How much can be won tax free from a gambling shop in Poland
According to this article there is a 10% tax on winnings:-
frixo.com/sbook/regions/poland.asp
These sites might be of help:-
e-playonline.com/poland-tax-on-winnings-when-do-you-have-to-pay/
practiceguides.chambers.com/practice-guides/gaming-law-2019/poland