Requirements for opening an account abroad are different. They depend not only on the country, but also on the bank.
Most often, to open an account in a foreign bank, it is necessary to provide a standard package of documents:
passport,
document on registration of place of residence,
permission to stay legally in the country.
According to local legislation, each bank may require its own list of documents, which may differ significantly from the requirements of Ukrainian banks.
Regarding Poland, you can open an account there without visiting a bank. But banks often require to provide:
Polish individual tax number,
address of residence in Poland,
valid visa or other documents confirming the legality of stay in the country.