Ever since version 3 of WordPress, it was no longer required to use a plugin to create a sticky post, as it is now an in-built feature. What it means to make a post “sticky” is to keep it at the top of all other posts on the homepage and in archives.
As you are probably aware, by default the post at the top is always the latest post, but when a post is given the “sticky status” is takes precedence over the “date” which is the value that usually determines the order that posts show up.
Quick Steps For Making A Post Sticky
1. Although probably unneccesary: install WordPress or upgrade to the latest version
2. Login to the WordPress Dashboard
3. Find an existing post or create a new one
4. Regardless of wheter in add or edit mode, locate the Publish panel at the top right (see image below)
5. Click “Edit” next to “Visibility: Public”
6. Below public put a checkmark next to where it says “Stick this post to the front page”
7. Click the blue “Update” or “Publish” button at the bottom right of the Publish panel and you are in business
Note: Multiple sticky posts will go back to the “date” value for secondary sorting.