Sci-fi story about a dystopian city - my draft

As a young man living in the desolation city, a place in Texas, it is where a father learned to jump and lasso bulls. He says to his son" Why did the cowboy break up with his guitar? " His son is wondering who in his family is so strong that he gets it from and says "I don't know dad, nobody in this town has many strings or brains for that matter".

When this boy was a kid, his father went to purchase oxygen in the store and there wasn’t any left. Turned out they had to move the whole town to a place near the wall.

There he once saw the door open in the
wall. The wall looks like it was built by aliens.

He remembers hearing people arguing then they disappeared behind the door in the wall

There weren’t nice kids in the new neighborhood. They were tough and acted like juvenile delinquents stealing to survive living by the wall. The boy is good at climbing and hanging from the ceilings. A lady was doing her laundry when suddenly he came down from the ceiling making her scream in fright while his friends laughed their guts out.

There is talk-that there is clean-oxygen behind the wall because why else would they evacuate their townsfolk near the wall.
The boy wants to find better oxygen and he knows that he is the strongest and the only one who can do it.

One day they didn’t find any oxygen in the store again. They had only days worth of supplies left.

I know they are hiding oxygen behind the wall from us, said the boy.

He started climbing the wall and he got attacked by mechanic spiders. He jumped on the first spider and moved it’s arms to throw the second spider down the way his dad taught him to lasso. He said "What do you call a cowboy who is bad at maths?" Then he ripped off it’s arms and kicked the second spider down and said "A rounding troublemaker."
He was able to attach the spiders limbs to his legs and arms which stuck to the wall. When he looked down he saw that the townsfolk already left without him. They just abandoned him to die. That means he was going to die unless he actually finds oxygen soon.

Suddenly he felt a violent shake that almost threw him off the wall. There was an explosion and part of the wall was blasted off.

He climbed around the remaining wall away from the smoke.

When he reached the top and started climbing down it seemed like the wall was connected to the ceiling and he continied crawling on the ceiling corridor. It was dark and smoke filled the air.

He saw the warning 10 percent oxygen remaining message on his gear.
It didn't matter that there was smoke and fire because he had enough air for now.

He looked down and saw people in respiration masks who were laying unconscious. He climbed down and saw that their oxygen tanks had been broken and oxygen was leaking out of them.