 He studied mathematics, philosophy, pedagogy, and new languages at the universities of Berlin and Greifswald from 1896-1900.In Berlin-Schöneberg, Oestreich was a teacher from 1901 and a Studienrat from 1905.He joined the National-Social Association and the Liberals Association to Friedrich Naumann, which he represented 1906-08 in the Berlin City Council, then the Democratic Union.