What should I do about this

Um, I made my own Idea first and posted it on musescore.com Another user ryacoli said that he is going to steal my stuff. He is stealing my Idea and I am very sad about that. Im just 11 and I dont know what to do about this. Im really sad, please help.

mine:https://musescore.com/user/36639554/scores/6576310?from=notification#co…

his:https://musescore.com/user/9233351/scores/6591083

Edit: Problem solved. Its clearly not plagiarism