What’s the plot of Wizard of Oz?

A girl runs away from home because a mean old lady wants her dog.

She meets a fortune teller who tells her to go back home.

She gets knocked out during a tornado.

Has a crazy dream.

Wakes up and realizes there's no place like home.

A real short version:  

A girl goes to a foreign land, and immediately kills someone by accident, and accidently kills her sister and then goes home.  

When a tornado rips through Kansas, Dorothy (Judy Garland) and her dog, Toto, are whisked away in their house to the magical land of Oz. They follow the Yellow Brick Road toward the Emerald City to meet the Wizard, and en route they meet a Scarecrow (Ray Bolger) that needs a brain, a Tin Man (Jack Haley) missing a heart, and a Cowardly Lion (Bert Lahr) who wants courage. The wizard asks the group to bring him the broom of the Wicked Witch of the West (Margaret Hamilton) to earn his help.

A woman waking up from a concussion.

The story begins in sepia-toned Kansas, where Dorothy Gale lives with her Cairn Terrier, Toto on a farm belonging to her Aunt Em and Uncle Henry. Toto bites neighbor Miss Almira Gulch on the leg, leading her to obtain a sheriff's order to have him euthanized. Miss Gulch takes Toto away, but he escapes and returns to Dorothy; she decides to run away to save her dog. Not far from the farm, she runs into Professor Marvel, a fortune-teller who uses his crystal ball to make Dorothy believe that Aunt Em is heartbroken. Dorothy rushes home as a tornado approaches. Aunt Em, Uncle Henry, and the farmhands take shelter in the storm cellar and lock it behind them. Dorothy has to seek shelter in her bedroom, where the window is blown in and hits her on the head, knocking her unconscious. The house is sent spinning into the air, and she awakens to see various figures fly by, including Miss Gulch, who transforms into a witch, flying on her broomstick.

The film changes to Technicolor as Dorothy's house lands in Munchkinland in the Land of Oz. Glinda the Good Witch of the North and the Munchkins welcome her as a heroine, as the falling house has killed the Wicked Witch of the East. As the Munchkin celebrate the end of their slavery, the Wicked Witch of the West arrives to claim her sister's ruby slippers but Glinda transfers them onto Dorothy's feet. Enraged, the Witch swears revenge on Dorothy and vanishes. Glinda tells Dorothy to follow the Yellow Brick Road to Emerald City, where she can ask the Wizard of Oz to help her return home. On her journey, Dorothy meets a Scarecrow, who wants a brain; a Tin Woodman, who seeks a heart; and a Cowardly Lion, who desires courage. She invites them to accompany her and ask the Wizard for what they lack. Despite the Witch's attempts to stop them with sleeping spells and other magic, they reach the city and see the Wizard, who appears as a giant ghostly head. He agrees to grant their requests if they bring him the Witch's broomstick.

As they make their way to the Witch's castle, the Witch captures Dorothy and tries to take off the slippers, but after they electrocute her, she realises that the slippers will only be removed after Dorothy's life ends, she turns over an hourglass full of blood red sand and leaves Dorothy to die. Toto escapes and leads her three friends to the castle. They ambush three guards, don their uniforms, and free Dorothy. The Witch and more guards pursue and surround them. The Witch sets fire to the Scarecrow, causing Dorothy to toss a bucket of water on him, inadvertently splashing the Witch, who melts until only her black witch outfit remains. The guards rejoice and give Dorothy her broomstick. Upon their return, the Wizard stalls in fulfilling his promises until Toto pulls back a curtain, exposing the "Wizard" as a fraud operating machinery. Admitting to being a humbug, he insists he is "a good man, but a bad wizard." He gives the Scarecrow a diploma, the Lion a medal, and the Tin Man a ticking heart-shaped clock, helping them see that they already possessed the qualities they wanted. He offers to take Dorothy and Toto home in his hot air balloon, revealing that he is also from Kansas, and was originally a carnival showman before his balloon escaped Kansas and brought him to the Emerald City.

As Dorothy and the Wizard prepare to depart, the Wizard places the Scarecrow in charge of Emerald City, with the Tin Man and Lion as his aides. Toto leaps from Dorothy's arms. As Dorothy pursues Toto, the balloon departs with the Wizard. Glinda then appears and tells Dorothy that she has always had the power to return home using the ruby slippers. After Dorothy bids the Scarecrow, Tin Man, and Lion goodbye, Glinda instructs her to tap her heels together three times and say: "There's no place like home." When Dorothy does, she awakens in her bedroom, surrounded by her family and friends. Everyone dismisses her adventure as a dream, but Dorothy insists it was real. She says she will never run away again and declares: "There's no place like home!"

Possibly when they teased the apple trees  to get fruit thrown at them to eat (?)

The Wizard puts out a contract on the Wicked Witch of The West. Dorthy and her friends become bounty hunters. 

Believe it or not , the whole thing is an allegory for going off the gold standard. 

At the time, Frank Baum was a strong OPPONENT of  going OFF the Gold Standard. 

He thought the wicked witches of the East and West,  ( The Bankers  and railroad barons of the East and the Newspapers Barons  of the West..The Hearst's)  were all in cahoots to TRICK people to believe in GREEN paper money,  (The Emerald City) ......and leave the Yellow Brick road,  (the safety of GOLD bars).......and the Wizards of Wall St. ....were all tricksters and charlatans,  using smoke and mirrors  to give people  fake goods.   (a fake heart, a fake brain, fake courage)  so they would believe in these pie in the sky....(hot air balloon)...worthless emerald green banknotes........that were NOT backed up by solid gold. 

There's no place like home, really means, there's nothing like the solidity of reality, rather than believing in silly dreams. 

But despite the wise tale.....he was on the losing side, and  we left the gold standard, for our now  totally worthless  emerald greenbacks. 

That's what the story is REALLY all about. 

About a girl who gets hit in the head, and dreams of a magical place, and wants to go home to Kansas.

A girl gets blown away from her home with her dog in Kansas in a dream by a tornado to a magical land and on the way she meets three characters and they head to oz to see the wizard so he can send her home to Kansas