Mine is, as people say, a single-mother household. I don't even know my father's face.
Literal
Our-place [topic-は] commonly say [attr-の] single-mother [gen-の] household is. Father [gen-の] face [obj-を] I [topic-は] don't-know.
俗に言う ('commonly called, what people call') is a set phrase for introducing a label that the speaker finds common or cliché. シングルマザー is a loanword used straightforwardly. 父親の顔を僕は知らない inverts the typical order for emphasis — placing the object first and the subject after. This kind of OSV ordering is a deliberate focus-shifting device in Japanese, putting the marked object ('father's face') at the start for emphasis.