To create a blog, first add a couple of categories (eventually grouped inside a parent category).
Now you can start creating posts: Posts › Add New, fill the content, choose tags, upload the blog main image via Featured Image and click on Publish. You can select only the child category of the category group if you wish.
Repeat the above steps to add more posts.
Note that you are free to insert anything in a post.
To list the posts, go to Pages › Add new and choose the Blog Default template from the Template dropdown from the Page Attributes box.
Assuming that you work with lots of categories / category groups and you want to create a blog template that displays posts from a category of your choice, make sure that when creating the blog template page, in the custom fields insert mediaconsult_blog_cat for "name" and the category slug in the "value" field.
You can see the slugs of your categories by going to Posts › Categories, but as a general rule, a categoy named "Buildings" will have the default slug buildings and a category named "My awesome stuff" will have the slug my-awesome-stuff.