It is wise to install Magento 2 Polish Language Pack on your Magento 2 store. Why I say that? Frankly speaking, if you want to go further on the international market, the first thing you need to concern is being sociable with the people living there and the shortest way to enter is synchronizing the language. Namely as in Poland, communicating in Polish will make you more convinient in eCommerce business or traditional business as well without creating any awkwardness for the visitors. - View it on GitHub