Careful with the CC0 license. I used one such thing in a video I made for YT years ago. Years later I got a Copyright citation because of it. I still had proof of the CC0 license I send it, thinking that's it... It wasn't. The music author had sold the fucking thing. It was no longer CC0 and they were claiming ownership of the video. I went into the video, removed the audio, thinking, what a crock of shit, and that it was done now...
It wasn't. I kept getting flagged even if the movie was silent, because the fucking song was still in the video.
So, in the end I had to delete the video. It was either that, or lose ownership of it. BTW, they were not interested in a license deal, they had me on the ropes and they knew it. In the meantime Google cancelled my AdSense account because of it. There went my 45 cents... and any future revenue.
So, be aware of that. I don't really know how you can protect yourself in that case. It is a rather ingenious trap if you think about it, they collect a bunch of people using the music for free, sell it to a rights collection company for a bunch of money, then disappear, or change their name. Poof. And now everyone is fucked and either have to pay whatever the new owner wants or lose the work made with the "free music". I would recommend talking with a lawyer. Maybe having a contract with the music author, or something...
If I ever do anything media related, I won't use music or sounds of any kind. But, that's me. I hope you have better luck and not get involved with those scammers, or you are smarter than me.
Peace