Can I use my own tracks in my own YouTube videos?

Hey there - guys, can I upload my tracks to my YT channel and make, let’s say, a video of 2 hours of medieval music. How do I prove I’m the author and I don’t need a license?

You can upload your tracks to YouTube and the only reason you could need to prove those are your tracks would be if you get a copyright claim which can happen if you registered that music for Content ID. In that case, the distributor of your music or some Content ID management system you submitted that music to would have some standard procedure where you reach out to them notifying them to release that claim, whether through their platform or directly as YouTube dispute letting that claimant it is your music and you are the author. Normally they would just need your name, your username on that platform where you submitted music for Content ID, or something else only you can see on that dashboard, that proves it is you, which depends on the company. Otherwise, you don’t need to prove to YouTube that is your music until the point you get some copyright claim.