If you need to do some last-minute shopping for essentials once you arrive, there are several stores here in town where you could probably find whatever you need. For an comprehensive listing of businesses in the area, visit dexknows.
If you would like to take a scenic drive to the coast, there is an outlet mall in Lincoln City (about an hour away). Highway 99W will take you directly there.
Another place to shop is the Woodburn Outlet Mall located off I-5 between Portland and Salem.