Foothills, you're doing fine!
One thing that I wonder about is that you cast on 240 stitches for the scarf. This seems like a lot for straight needles. Did you cast on to knit it the long way? If you need to use straights, you should be able to knit it on the short side with fewer stitches. The stripes will run the short way, but unless you can get a hold of circular needles, which are two needles connected with a cable, I don't think it'll work too well. If your stitches fall off the needle, you're doomed.
Since you're so new, watch the videos, and knit a few small pieces, as April suggested. You'll get a better feel of knitting before you attempt a scarf.