We get the original premise of the boy in the escape pod leaving Krypton as it explodes and lands on Earth (with a meteor shower) and is adopted by the Kents. We get bits and pieces of Clark's life as he begins developing his powers at a young age (minus flying) and his parents begin to take notice. From there it's pretty much like the original Superman movie but with Clark more unsure of his future after high school and whether he should stay on the farm or move to the big city. His dad dies and tells him to move on with his life with his final words. The distraught Clark eventually gets a sign from his ship that suddenly gets up and flies off into the horizon, leaving behind a crystal.
Clark leaves the farm behind and goes in search of answers and starts by following the ship to Antarctica where it's there waiting for him. As he approaches it, the crystal flies out of his hand and buries itself into the snow as it grows into the Fortress of Solitude. There Clark learns of his origins and what his goal in life should be which is to give hope to Earth for peace.
Like in Batman Begins, Clark goes through a training process to hone his abilities and eventually learns the secret of flight. We learn that Kryptonite is the Kryptonian version of like radium and that Jor-El was like a nuclear physicist that worked with it. The yellow sun enhances it's radiation so that it affects Kryptonians even more. He and Jor-El decide to create him an outfit which is inspired by outfits worn by the ancient heroes of Krypton (which becomes the superman costume as we know it) which includes a blanket sewn by Lara-El which was made to protect him from radiation (but is only effective if airtight). Years later, after his training is complete, he's off to save the world.
We get the basic Clark Kent, reporter for the Daily Planet but rather than a nerd that Lois isn't interested in, he's more of someone in the "friend zone" and thus unable to make a move. Lex is the CEO of LutherCorp. but is feeling a sense of emptiness in that he should be happy with having everything but feels something is missing (btw, he's not the main villain of the movie). Superman sightings have happened all around and is confirmed when he thwarts a bank robbery attempt and becomes a public hero. However, he prefers to be more of a rescue worker than a crime fighter and wishes to save lives rather than interfere with the law. Lex notices Superman and wishes to be like him, a savior, when his satellites get a message from Brainiac who wishes to trade all the information on Earth for the knowledge he has acquired over the years. Lex acts as a delegate between Brainiac and the world leaders as he negotiates the trade. All believe Brainiac to be benevolent. When Superman discovers he was the one who destroyed Krypton, he tries to convince Lex that he's evil. However, Brainiac tells Lex that Superman is evil and gives him Kryptonite to kill him believing he will be Earth's savior. Brainiac becomes impatient and decides to steal the information from Earth which prompts the police to try and stop him. The police also stop Lex from killing Superman but can't stop Brainiac who has a ship hovering above Metropolis shooting a beam through the ground trying to make it's way to the Earth's core. After an epic battle, Superman stops Brainiac and destroys the ship before it can finish the job. Superman becomes the hero and Lex looks like a douche for trying to kill him which makes him jealous and angry (prompting him for future villainy). Lex keeps a bit of Kryptonite with him at all times and bits of Brainiac's ship scatter all over Metropolis which also prompts the technological creation of future Superman villains (much like the prison break from Arkham did for Batman). Superman secures his place as the hero of Metropolis. I call this movie THE LAST SON OF KRYPTON.