Question: are the stormtroopers in episode 4 clones?
Answer: Clones were phased out of the Stormtrooper Corps shortly after the end of the Clone Wars, and were replaced with non-clone volunteers. Out-of-universe, Pablo Hidalgo has confirmed that the stormtroopers are not clones as of the events in Star Wars Rebels (which occur 5 years before the events of Episode IV).