Thank you for writing in, two things I can think of why you don't see the text formatting section on your text/headline element.
First, if you are using a Classic Text or Classic Headline element which has limited options. The font, color, and other styling of this classic elements are controlled generally in the Theme Options > Typography
It is also possible that you're using the (new) Text/Headline element but the Advance Mode option is not enabled. In Cornerstone see Settings > Preferences > Advanced Mode
Hope this shed some lights,