This workflow covers the process of exporting a still frame from Premiere.
If Premiere is not open, open it.
If you have not set up a project yet, please refer to this wiki:
|Adobe Premiere Pro - Get Started Using Premiere - Project Setup
Move your playhead through Premiere until you find the single frame that you would like to export. Park your playhead
Click the "Export Frame" button
Name your Still frame
Select 'Format > JPEG'
Browse to where you'd like to save
To create a zoom and pan effect on your still image, go to this wiki here.