Welcome to knitting and to KnittingHelp!
Long straight needles may take a bit of time to get used to. They seem to be rather awkward and in the way. You're not alone in that and that's why many people switch to circular needles. They hold more sts, let the project fit more comfortably on your lap (especially large items like blankets) and you won't frighten you seatmate on an airplane. You use them to knit back and forth just as you do straight needles and you can also use them to knit tubes.
Take a look at the videos under the Free Videos tab at the top of the page, especially the one under Geting Started, Demo of a Small Project and under Cast Ons. Try the knitted cast on or the long tail cast on which are both good to know and relatively easy to do.