Though your question is vague, the most common question about Heminway's story is how does Macomber change. The answer is quite simple: he becomes the ideal Hemingway male. That is he develops pride, strength, and machismo. He is no longer the coward who was easily bullied and manipulated by Margot. Once Wilson sleeps with his wife, Macomber's hatred begins to awaken in him the desire to finally take control of his life.
Just contrast how Macomber acts right after woudning, and then fleeing from, the lion. He is a disgrace. When they first spot the lion, he is too scared to get out and asks if he might not shoot it from the vehicle. Then when Wilson tells him to get out, his legs hardly move. And finally after wounding the lion, Macomber feels sick to his stomach. However, once he realizes that Wilson has slept with his wife, Macomber becomes angry. Note how he changes when they go hunting buffalo the day after the episode with the lion. Macomber is the total opposite of what he was earlier. Then Macomber is so keyed up to begin hunting that he almost starts shooting at them right from the vehicle. As they tear off after the buffalo, they are hanging off the car, crashing along the terrain. Then they stop and he lands on the ground and begins firing away - without a hint of fear. At least Macomber has had a taste of what it is like to live as a Hemingway hero rather than living the rest of his life as a coward bullied by his wife.
This answer is based on your email response asking you to clarify your question. You responded, "How does the character of Francis Macomber change from beginning to end?"
In the beginning of the story, we discover that Macomber has a lot of guilt about running away from an encounter with a lion. His male pride is wounded and the wound is kept open by his wife, Margot, who often brings up the incident sarcastically. She makes it clear that she does not respect Francis.
Wilson, Francis's hunting partner on this safari, does not respect Francis either; so much so that Wilson and Margot have a fling right under Francis's nose. Neither one seems to care much when Francis finds out about the infidelity.
Incensed by their disrespect, Francis is infused with a new drive. He and Wilson go after some buffalo. In a series of what may or may not have been mistakes, Margot shoots Francis in the head. Thus, the ironic title, "The Short Happy Life...". Francis brief stint in the macho spotlight is short-lived.
What does Macomber…what? What does he do? In the story itself, he tries to shoot a lion on safari, panics, and then tries to make it up by standing his ground and shooting a buffalo. However, just before he can shoot, he's shot down by his wife (who claims it was an accident).