Hey there!
It's slightly more complicated as PeerTube is spread out on many servers, so you have to choose a server, but once you've done that it's pretty similar to uploading to YouTube.
I've done a publishing guide that covers how to do it, including highlighting the differences to YouTube:
https://fedi.tips/how-to-publish-videos-and-audio-on-peertube/
By the way, if you're wondering why it's on many different servers, reasons are here:
https://fedi.tips/why-is-the-fediverse-on-so-many-separate-servers/