The further into Polish I get the more it feels like Romanized Russian.
There is no separate alphabet skill as these are just diacritics, special characters. You learn the pronunciation while doing the course.
"ę" is nasalized "e". It's like Spanish for "Euro".
"ą" is nasalized "o". It's more or less like the vowel in "rose".
"ł" is like "w" in English. While Polish "w" is like English "v".
I disabled the female voice (for the listening exercises only) because she seems to say "Ja mam mleko i chle", but in general I think that both voices say "mam" correctly. Plus "Ja mamy" is just undoubtedly grammatically wrong (although yes, I know it's the very beginning of the course so people haven't learned it well yet).