You can choose one of three pre-defined blog templates in the Theme Options. Just create a new blank page titled 'Blog', then set 'Blog' as the 'Posts page' in Admin->Settings->Reading under 'Front page displays'.

If you already have, just create new grid or use an imported style and choose postst as item source. Next, insert Essential Grid element on this page and choose one of the grid layouts. More information can be found in User Manual.

Comprehensive documentation on Essential Grid can be found here:

http://essential.themepunch.com/documentation/