Original: At the age of sixteen he was apprenticed to an apothecary, his father's profession, subsequently becoming an apothecary himself, and in 1839, at the age of 20, wrote his first work (Heinrichs IV.
Simplified: At the age of sixteen he became apprentice in a phamacy and then a pharmacist himself (like his father). In 1839, at the age of 20, wrote his first work (Heinrichs IV.