I love your energy, keep it up!
Well, since the video is for your son's birthday, hmmmmm. The idea in my head is that not only make it creative, but make a video that when your son becomes 20 years old he could play the video again and actually understand and comprehend the message in the video, he could look back at all the years and live his years all again through the video you are about to make.
Hear me out, picture yourself in a bubble far far away from the world in a far away orbit of the universe. It's just you, the bubble and your son.... let's imagine he could properly understand every single word and gesture you make perfectly, what would you like to tell him? imagine what you would want him to know in a bubble (your life) that revolves around him without the world there to poke and disturb your peace?... put that into words and leave it as a message in the video for your son to one day watch it again

wishing you the best of luck