Knitting a pattern

Hello, I have a question. I’m attempting to knit for the first time from a pattern. Here is the link
Anyway, I was trying to learn how to keep the yarn going across the back. I watched some the videos posted, but the instructor (I don’t know her name) said you should only go about 5 stitches and then chanfge yarn. If you look at the pattern, you’ll see right above the teeth, there is a long line of black and now the black is on one side and white at the other end. I should mention, she made a hat, but I’m trying a flat piece.
Any suggestions? :shrug:
Ravelry ID: Gavinsmama:shrug:

What she is talkinng about is wrapping your yarn that you are carrying across so that the working yarn traps it against the hat so you don’t have long stretches of the unused yarn hanging.