Select Guided > Fun Edits > Double Exposure . Now in the Right Panel, click on the Graphics icon to choose a photo from the Photo category. If you wish to use your own assets, choose Add Media or Project Assets. Note that you can only select one photo.
Drag-and-drop the photo on the track Video 1 in the Timeline.
Click play to see the final result. To export the final output, select File > Export and Share. For information about various exports and share options available, see Export and share your videos.