I would go to the Knit stitch next.
If you're working the Stockinette stitch pattern (there's a video about that too), alternate one row of all knit with one row of all purl. What Amy meant in the video is that if you are doing this type of pattern you should start with a purl row after doing the long-tail cast-on.
Don't worry about the "tail" for now.. you can weave it in later. Though if it's so long it's getting in the way, you can chop off all but a few inches.