I was able to successfully change the name of the category.
But unfortunately, I couldn’t change the name of the “staff” channel. But that’s okay.
As I said, you can edit the name like you can edit every channel’s name.
Click the channel’s title:
and edit the name:
2 לייקים
Thank you!
I finally found out how to get into the settings of the channels. 
לייק 1