Well, you did get a good deal. The price was good. Cotton yarn doesn't have much give, though, so it might be harder than you want just starting out.
I would suggest that you go to a discount or craft store (like Michael's or Joann's) and purchase a worsted weight acrylic (or wool if you don't like the feel of acrylic). Don't buy any fun fur or hairy yarn, just plain yarn. Get a light color, it's hard to see the stitches when you're just starting.
Then cast on some stitches. Rip it off, cast on again. Try knitting some rows and then try purling. Just play with it so that you get the feel of what you are supposed to do. If your knitting is too tight, hold two needles together while you cast on and slip one out when your stitches are on. It will keep your cast on from being too tight.
Knitting takes practice, but it's very rewarding. Good luck!