What is the ruling on performing Friday Prayer in a mosque where the sermon is in Turkish, when only a small part of it is understood, due to the closure of other mosques in Poland?

The Hanafī jurists permit the sermon in a language other than Arabic, and this is the fatwa issued, and it was chosen by the Fiqh Academy, especially for non-Arabic speaking countries, due to hardship and need. Therefore, you can attend the sermon and prayer with them to fulfill your obligation for the obligatory Jumu'ah prayer.