On the Tips page, there's a video called Demo of a Small Project. You could look at that first to see the whole picture of how a piece is knit from cast on to bind off. Then begin with cast on videos, see which you like better - the simple or loop cast on actually isn't a good one to start a project with, it's hard to knit into, so use one of the others. Then you can practice the knit and purl stitches, then casting/binding off. You can refer to the Demo video again once you start working a few rows to see how you end a row and start another one.