WordPress automatically assigns the default category to a single page. This is a simple way to exclude certain pages, for example, a contacts page, from displaying in your search results. A simple way around this is to create a new category, in this instance I have called it pages. Once the category is created hover over the newly created category and look for the cat-ID number as shown below, remember it or write it down.
This is an alternative to my recent post WordPress Blog display using the more tag
as that method worked on my testing server but it decided to give me 404 errors whilst navigating.
Here is a simple solution of how to display one full post on your WordPress homepage and sections on other pages such as archives page and categories page.