There might be a misspelling in 'one upom a time story'. I assume you mean 'once upon a time'. Well, once upon a time, there was a little girl named Lily. She lived in a small village at the edge of a big forest. One day, while exploring the forest, she found a beautiful, shiny stone. She took it home and soon discovered that the stone had a magical power. It could make plants grow instantly. So, she used it to make her family's garden the most beautiful in the village.
I think it should be 'once upon a time'. In that case, it could be a story about a princess locked in a tower. A brave knight heard about her plight and decided to rescue her. He rode his horse for days and fought many monsters on the way to the tower. Finally, he reached the tower, defeated the dragon guarding it, and rescued the princess.
It could be the story of the actors in Hollywood. They are constantly striving to 'one up' each other in terms of fame, roles, and success. Each actor has their own journey filled with auditions, rejections, and finally getting that one role that can change their career. For example, Leonardo DiCaprio, he worked hard for years and finally got his Oscar, which was like 'one upping' his previous status in Hollywood.
Well, a 'one line at a time story' is like a unique form of storytelling. Imagine a group of people sitting around. One person starts with a line, say 'Once upon a time in a far - off land'. Then another person adds a line like 'There lived a curious little girl'. And so on. Each new line moves the story forward in an unexpected way. It can also be something a single person does, writing one line at a time, perhaps letting their creativity flow in short bursts and seeing where the story goes without planning too much in advance.
The 'one at a time story' might be a story - telling technique where events are presented one by one. For example, it could be like a mystery story where clues are given out one at a time to keep the audience in suspense. Or it could be a simple narrative about a journey where each step or encounter is told separately, one at a time, to build up the overall experience of the story.