Complex sentence: He dropped out of high school in eleventh grade, to pursue an acting career, and subsequently took college courses (at Pasadena City College in Pasadena, California and University of California, Los Angeles extension).
Split into simpler sentences: He dropped out of high school in eleventh grade to pursue an acting career. Subsequently, he took college courses (at Pasadena City College in Pasadena, California and University of California, Los Angeles extension).