Blogs can be written by team members marked "blog users" or blog managers. In larger teams, typically there would be select few people who are authorized to write/edit blog posts for the project. New blog posts will be in "editing" state by default. They need to be published for others to view. Only blog managers or project admins can publish posts.
For managers and admins, there will be buttons to create and manage posts at the top of blog related pages. When creating a new blog post, a cover image is mandatory. If you are adding images in the content, it will also appear in list of possible cover images and a separate image need not be added if you don't need.
Admin activities like deleting and restoring can be done from the dashboard. Blog posts can't be deleted. If you don't want a blog post, unpublish it or re-use it for a different post.