I would like to have my own music for my videos. But I don't know how can cave our own work?

I don't need patent rights, but how we can tell it is our own work?

I am asking this, because when I upload the created music in YouTube or somewhere, they should not get strikes by copyright bots, and what should I do if I get any strikes to my own music?

Thanks for sharing @jerrybanfield and hope you help me out at the above situations, too.