You can find a list of Card Creator Tutorials here:
The Card Creator UI on this video is quite outdated as they were recorded over a year ago.
You can also find more helpful and responsive advice by going to the #card-creator-help channel in Discord. We (the developers) were very happy to find that players do a great job of explaining how to create cards to new users. We assumed that we would have to make lots of videos, and possibly interactive tutorials explaining how to create new cards; luckily, our awesome community does a great job answering questions quickly. Come say hi, don't be a stranger! It'll help you make cards faster :)