How do I edit/delete my own Story-Pages/-Blocks?

As long as there are no submissions to your Story-Page or -Block, you are able to edit or delete it as you like (besides the exceptions mentioned above).
When a Story-Block has been submitted to your Story-Page, this function is limited. Only moderators (and trusted users, see ’What are “Trusted users”?’) are able to delete Story-Pages and edit/delete Story-Blocks in this constellation.