When you have dragged in a contentblock it's possible to change it's settings. Under the blue button you can adjust the following settings:

Contentblock width
Change the width of the contentblock or set if fullwidth 100%

Align options
Align the block left, right or center

Padding / whitespace 
Change the whitespace at the left or rightside

Duplicate the element

Delete the element

Horizonal & vertical whitespace/margins
With the green arrow in the right top of each element it's possible to change the top margin for each block. When the same arrow appears in the right bottom of an element you can change the height.