The easiest way To display section breaks so you can delete the ones you don't want, use Show/Hide.
Click Home > Show/Hide .
Section breaks look like this:
Select the section break you don't want, and press Delete.
When you delete a section break, Word combines the text before and after the break into one section. The new combined section will use the formatting from the second section (the one that followed the section break).
To add new section breaks, see Add a section break.