It looks like this can be accomplished very simply. Place the edited and produced video on track 1.
Open Gimp. Create a new 16:9 image with a transparent background. Do a Gradient Fill top to bottom. Cut out the section for the video to show through leaving the L shape. Put this on track 2. At 28 seconds in the video fade this section in. Do your titling with no effects on track 3.. Create the images for the Frets and the FingerBoard with Gimp. Place and resize them with PiP Designer on the lower tracks to show on the left side.
You can choose to do this with any image software that you are more familiar with. You can use more tracks if you think it will help with your thoughts. Hope this help you get started on your own.