ترجمه - لهستانی-انگلیسی - W ten Wigilijny Wieczór niech ...

Wigilÿny --> Wigilijny
Nouvego --> Nowego

Corrected! Thanks Aneta.

About the translation... just a few adjustments:

"May wafers and (-) traditional Polish carols unite our thoughts and hearts on Christmas Eve, and may all the days of the New Year be accompanied by a smile."

What do you think?

In Polish words "wafer" and "carol" are singular (it means "sth" in general), but if you think it sounds better in plural in English, I believe you, dear Lilly.
I agree with the rest of your corrections too.

Exactly, when generalizing we use plural in English
Would you edit so that we can set a poll?