Nothing. Yes certain Wiccan branches have degree systems they do not determine what spells you can cast, they determine how much you've studied. [Also, I don't know of any that go up to 10]
If you're not Wiccan, you can ignore the degree completely. Anyone can cast spells, but certain 'rules' are actually guidelines exclusive to certain paths. [Like the threefold law or Reds, it's a Wiccan concept not a law of Paganism] if you don't believe in it, don't worry about it.