Cooking a turkey in an electric roasting pan for the first time
You can absolutely cook a turkey without a wire rack.  I have done this for years.

What I suggest is laying down a grid of celery and carrot sticks, to elevate the turkey a little bit and keep it from sitting in the juices that will come out during cooking.

These aromatics will then lend their flavor to the pan drippings, and help you make a fantastic gravy.



Another approach, which I do not like as well, is to crumple aluminum foil into a snake-like shape, and coil or snake it around the pan to serve as a makeshift rack.  

This works well, but doesn't offer the flavor benefit that using aromatic vegetables does.