Complex sentence: After graduating from high school he joined the Army, then went to college, where he earned a degree in English and became interested in acting, so after graduation he studied at the Actors Workshop in San Francisco for two years.
Split into simpler sentences: After graduating from high school, he joined the Army, then went to college, where he earned a degree in English and became interested in acting. After graduation, he studied at the Actors Workshop in San Francisco for two years.