First notebook entry: Introducing myself

안녕하세요!!!
저는서비아입니다.
저는폴란드"에서" 왔어요

에서 is correct. XD

And "폴란드에서 살아요" will be more profer sentence unless you are already in Korea.

Because "폴란드에서 왔어요" means "I came to Korea from Poland" in Korean.

Good luck!