there is nothing under "recent articles"
How many posts do you have in the blog that you have published? In Oxygen, there is no way to show posts in both the slider and the Recent Articles area. It's been designed to not to have duplicated posts on the page. Also note there is no option to display more than three Recent Articles on the Showcase Page template.
I checked from other users, on the showcase page, there will also be brief view of each articles under "recent articles" column.
It is a Page Template. Go to to screen options on the top right hand corner of your Admin page and select and include the Pages Module
Page – Likes and Shares, Page Attributes, Featured Image, Discussion, Comments, Page Revisions, Slug, Author, Revisions, Writing Helper http://en.support.wordpress.com/modules/#list-of-modules
Then see the Oxygen theme description page for the information you need: http://theme.wordpress.com/themes/oxygen/