What is Youtube Studio?
Youtube Studio is the name of a section of Youtube used by people who upload videos (e.g. Youtubers) to manage the content they uploaded, view analytics, and perform other creator-related actions.
Youtube Studio isn't a paid product or anything like that. It's a stylish term for "dashboard for uploaders" that Youtube chose for their dashboard. If you don't upload videos to Youtube, you'll probably never need to interact with it.