To learn a new behavior, the trainer needs to reinforce every part of the trick in steps.
While humans can learn to do things by watching a video, it's unlikely a bird will learn to do a physical "trick" by watching a video (there's no motivation). I would suggest that you Google "positive reinforcement in training" which is how most any animal learns. Also, any "trick' that a budgie is to learn, has to be a behavior that they would do naturally.