Hi Vladana :)
Is Polish popular as a language in your country? (due to the closeness in location, and the similarities in the language themselves?)
Hope you are well!
In elementary schools kids learn English first and few years later get a second foreign language. When I was a kid it was up to the school to choose which second foreign language the kids will learn. The choice was very limited - German, French, Russian. My school picked German. I hear that nowadays it's up to the kids to choose which second foreign language they will learn and that they also have more to choose from. One language I know is being studied at schools is Chinese due to more and more Chinese companies doing business here.
In high-schools it is usually English and second foreign language (which is normally the SL learned in elementary school though if a child wishes to switch to another language they can but they will not be able to start from the beginning) + Latin in grammar schools.
Adults mostly learn German. We, regrettably, have a massive brain drain to German speaking countries so teaching German has become very lucrative.