I'm not sure if this mite be useful but my eng teacher always told us to write about things u are familiar/interested in, whether that be soccer etc, as ur story will be much more believable and genuine rather than writing about something you kno near nothing about.
Another tip, ur story doesn't necessarily have to be about something concrete nor have a ingenious plotline. It could something creative and simple such as a daydream to the moon then realising you've always wanted to be an astronaut (thats wat my story in the hsc exam was about
) .Take inspiation from something... anything and try to mould it into a story.
Hope that helps