I'll recommend the book that made me want to write short stories:
The October Country, by Ray Bradbury.
This volume contains one after another of the most astoundingly wonderful short stories ever written. And reading stuff of this sort is how you'll learn how to write short stories.
No short-story cookbook will do that. Read stories. Read a hell of a lot of 'em. Read widely, every genre. Get your bone marrow to understand how the best stories work, and why.
Read:
"The Lottery", Shirley Jackson
"Afterward", Edith Wharton
"The Nine Billion Names of God", Arthur C. Clarke
"The Wall", Jean-Paul Sartre
"The Gift of the Magi", O. Henry
"A Touch of Nutmeg Makes It", John Collier
"Everything that Rises Must Converge", Flannery O'Connor
"The Hoard of the Gibbelins", Lord Dunsany
"The Lagoon", Joseph Conrad
"Paul's Case", Willa Cather
"Wine in the Desert", Max Brand
"The Black Monk", Anton Chekhov
"The Horla", Guy de Maupassant
"The Snows of Kilimanjaro", Ernest Hemingway
"The Country of the Blind", H.G. Wells
"The Yellow Wallpaper", Charlotte Perkins Gilman
"The Tell-Tale Heart", Edgar Allan Poe
"To Build a Fire", Jack London
"The Open Boat", Stephen Crane
"Silent Snow, Secret Snow", Conrad Aiken
"The Rocking-horse Winner", D.H. Lawrence
. . . and a hundred others. Pay attention to what makes them work.
Then go write one better than any of them.
caw