Change Featured Content

Dear forum,

I customizing the Expound theme for my blog: https://ntropy.de/

I′d like to change the featured content.php so that that big article right below the header is fixed, while the smaller articles can change. (I′d like to separate big articles from “smaller” articles, so they can remain longer. The smaller section should change by date still.

Then I′d like to know how to reduce the height of the “middle part”, the part where the 4 articles are listed so that the sites (FB page etc.) is not that “far” away.

Thank you in advance
Phire