Dare to join the camera in your casual essence and with any feeling you are experiencing in the moment. It will be not the video where you need to impress or please anybody. That said, it is okay to forget happy face or anything that is not true for you on that moment.
While you watch to the camera, relax, breathe, feel and connect in the aliveness in you by focusing your attention to your physical senses. Feel your feet in the ground. Take one or two deep breath to slow down your mind. Feel how breath moves your lungs. Notice any tension in your body, maybe in your face, on your shoulders... Observe it and let the body relax. Don't try anything. Stop trying. Just feel the life happening in your body sensations. Keep the focus in the now. Just listen, sense, observe, and relax. Be conscious of the thoughts and emotions, no need to think or analyze them, just being conscious is enough. While this is not a test to be passed, you don't need to worry about anything. This is the space where you don't need to succeed, you don't need to pretend.
Just observe and experience the life on that specific moment. Focusing on your sensations, is easier outdoor than indoor. Feel free to record your video in the woods, if you like.
Try to avoid speaking. If possible, just witness your need of talking. The value of silent witnessing is the increasing awareness when you just observe what is happening inside you. More important than speaking out the content of your thoughts, is to be aware of them. Remember that you do this for yourself. Give yourself this moment to let go of anything that is going on in the world, and to connect deeper into yourself, by relaxing and being present.