At the beginning of your pattern there should be a subtitle where they indicate the MATERIALS you need to make your garment. May be, there, they are asking you, besides your dpns, a pair of circular needles for a specific number.
Patience, persistence and love are the main ingredients for wonderful knittings.
Yes, it may also depend on how many sts you're to leave unworked and how many you're to continue knitting flat (or back and forth). If the sts to be worked back and forth fit on one dpn, you can just continue with two of the dpns. Leave the other st to hang out or put them onto scrap yarn until you need to work them. You start, as the pattern says, by turning the knit piece just as you would at the end of a row.