Trying to create a video from a beach scene that has a wiseman and a young lady watching the sunset

I am trying to create a video where a wiseman (image attached) and a young lady (image attached) approach and sit on a beach (beach scene attached) watching the sunset. The young lady turns to the wiseman and asks "What makes someone truly powerful?". The wiseman replies "A person who has control over their mind." The young lady then asks "And what does that control lead to?". the wiseman responds "The ability to realize their full potential."

How do I do this in Firefly? I have tried  a few things but cannot get it to work. The closest I got was in the video attached but i did not use my images. Video is attached.

Cheers

Geoff

Beach at sunset.pngWiseman.pngYoung lady.png