Замените придаточные предложения герундием с предлогом after. ОБРАЗЕЦ. When she bought everything she needed, she went home. — After buying everything she needed, she went home.

My son got a job after he left school.
After she took her daughter to the kindergarten, she went to the library.
When the children came home, they started playing computer games.
After I thought for a while, I finally decided to buy that hat.
When they got off the train, they went straight to the hotel.​