Changing the Front Page Layout in Joomla!
The front page has two sections of articles: the leading and the intro articles. The leading articles disply the full width of the article area, and the intro articles can appear in the full width or in columns.
You can change the number of leading articles and trailing articles and the number of columns. (first blue arrow)
You can also change whether the columns fill across or down – choose across if you want them to be balanced. (second blue arrow) This setting is in the Parameters (Advanced)