The channel name is a unique identifier of your channel on this and all the other instances. It's as unique as an email address, which makes it easy for other people to interact with it.
Currently this instance doesn't allow for user registration, but you can find an instance that gives you the possibility to sign up for an account and upload your videos there. <x id="LINE_BREAK" ctype="lb" equiv-text="<br/>"/> Find yours among multiple instances at <x id="START_LINK" ctype="x-a" equiv-text="<a>"/>https://joinpeertube.org/instances<x id="CLOSE_LINK" ctype="x-a" equiv-text="</a>"/>.