Fastest way is to scale up the photo.
Photo's seldom have the same dimensions as video, so you will always loose some of the picture frame if you want it to fully fit the frame.
If this is not what you want post a sceenshot to see what can be done.
The two white frames are guides.
Right click in the monitor and turn off Safe Margin.
For making the picture full screen.
Select in timeline
Open Applied Effects
Twirl down Motion
and tweak the Scale.