Making money while you sleep can be very exciting. However, when you are just starting out, you will probably only be making pennies. Unless you build up a quick following and work full-time on creating new content, it will take time to start earning anything substantial overnight.
From my personal experience of trying out just about every method for bring in passive income, most methods will probably not work. What does work, however, is being able to write and/or produce videos on popular topics or for you to get lucky and have something trend. Even then, you will need to continue producing more and more content because after something trends, it also has a fast decay rate.