Most professional videos begin and end with a black screen. It gives a clean beginning and a definite ending to a movie.
You can do this for your video by adding the Fade In, From Black icon to the first picture in your video, and the Fade Out, To Black icon to the the last.
These effects are located in the View video effects menu. Add them by dragging and dropping, as you did with the Ease In and Ease Out effects. You'll see a double star on the pictures, indicating two effects have been added.