Best answer
Hi!
When you say video marketing content, what are you referring to? What is your channel about?
Some tips for you:
1. Have a look at your competitors/people that have a similar channel to yours. Don't steal their content, but have a look at what they make videos about, which of their videos have a lot of views and engagement, and what topics they cover. As they will have a similar audience, you can get a first overview of what might be interested to them.
2. Go to Google and have a look at what people are searching for related to your channel's topics. People like content that help them solve their problems and when they have a question they usually google it. That's why Google is a good place to find topics for videos.
3. There are some nice Youtube SEO plugins that help you optimize your youtube channel and videos.
Hope it helps