Posts don't show on homepage under slider

I’m using the .com version and I want the posts to appear under the slider, so I followed the instructions:

“Choose a primary featured category in Appearance → Theme Options. To feature additional categories, go to Posts → Categories and assign your primary category as the ‘Category parent’ of each additional category you wish to feature.”

I checked the steps many times but I still cannot make it work. Any clue about what could be wrong in the emerging soccerunitedf7.wordpress.com site? I’ll appreciate any help.