It's hard to say for sure. If the author or creator has stated that it's based on real-life, then it might be. But often, stories like these can be a blend of reality and imagination to make it more engaging.
In a cheer competition, there was a story about a small team from a rural area. They had very limited resources but their spirit was high. They practiced day and night on a patchy field. Their story inspired many other teams to not be deterred by lack of facilities. They finally made it to the regional finals and won the hearts of the audience with their sincere and energetic performance.
A 'cheer you on fanfic' could be a fan - created story that focuses on characters supporting or cheering on other characters. It might involve scenarios in a particular fictional universe where one character gives motivation and positive vibes to another, perhaps in a sports - related story, or during a difficult time in a character's life.
One Christmas cheer story is about a little boy named Tim. He lived in a small village. On Christmas Eve, he noticed an old man sitting alone in the cold park. Tim went home and got his warmest blanket and a plate of cookies his mother had made. He gave them to the old man. The old man's face lit up with a big smile. That simple act of kindness spread Christmas cheer not only to the old man but also to everyone who saw it in the park.