Video marketing can appear to be quite casual. Videos can “go viral” with no advance warning if they catch people’s mood in the right place at the right time. Or they can skulk in a backwater with almost no views. Or anywhere between those two extremes.
What you need to include in your video depends on what your desired end result is.
If your desired result is a viral video that breaks almost every viewing record on YouTube then I wish you good luck but you’re probably better off looking through the most popular videos on YouTube and hoping you can use those for inspiration.