Hello, I love the song!!!! In a few months I am going to participate in a short film contest and I was wondering if I could use it for my project. I wait your answer!!!
Unfortunately as I don't own the song and am not the copyright holder, I can't say yes or no. However, I have it uploaded here without issue, so I'm sure using it in your film would be fine.
[THIS IS NOT LEGAL ADVICE. I'M NOT A LAWYER.] Just because you can use it on youtube doesn't mean you can use it in the contest. RU-vid has special "permission" to use the music because they self-moderate their platform through their content-id system and compensate copyright holders with ad revenue if the copyright holders choose to not take the video down. Without this agreement, youtube could just die overnight in a hellfire of lawsuits if the music industry chooses to. I know it's much, much, much more complicated than that, but I don't want to write an essay about it. I'd do more research and try to get permission from the copyright holders.