From the “Status & Visibility” panel on the right-hand side of the edit blog post page, tick the “Stick to the frontpage” box then hit the “Publish” button.
How to create a post that always stay at the top of the blog list
From the “Status & Visibility” panel on the right-hand side of the edit blog post page, tick the “Stick to the frontpage” box then hit the “Publish” button.