I am trying to find the exert feature on my page.
Attached files: Screen Shot 2018-11-15 at 12.58.23 PM.png Screen Shot 2018-11-15 at 1.01.44 PM.png
The excerpt field can be enabled by clicking the "Screen Options" label in the top right corner on the page, click the "Excerpt" checkbox and then scroll to the bottom of the page.
The "Screen Options" label can be seen on both screenshots you've attached.
Change the featured page widget image and text