> If I were a native speaker? Then for sure, by definition I could not have a wrong accent (whether it's understandable is a different question.)
You're Polish. There aren't many places outside of Poland where Polish is a native language - I'm not sure if there are any at all if you narrow it down to places where it is an official or majority language.
I was talking about Indian English and Phillipine English. Indians and Filipinos often speak those varieties of English natively. The reason they exist is literally because the British Empire brought the English language with it when it invaded them and they had to learn it to adapt to their conquerors. But that was a long time ago and now you have literally generations of native speakers of those varieties of English just as you do in the US, Ireland, Canada, South Africa or New Zealand[0].
This is different from a Polish non-native speaker of English or German, or a non-native speaker of Polish having "an accent".
[0]: I'm intentionally omitting Australia because Australian English seems to have a more homogeneous history, being mostly the product of different British varieties of English. New Zealand English shares a similar history but is distinct because it also took influences from its indigenous Māori language. Canada and the US of course can trace their varieties back to British settlers but likewise saw many influences from other settlers, slaves, indigeneous peoples and later immigrants. South African English again goes back to British settlers but includes varieties natively spoken by members of the majority of its population unrelated to those settlers. Ireland's native population - as in India and the Phillipines - adopted its variety of English due to British conquest.