How to make a face between circles? trying to make a face between the selected circles for a disk shape
  SHIFT TAB should let me select edges then i should be able to make a face, correct? however, the selection to select vertices, edges isn't showing up and when i hit f, a third larger circle appears? what gives? beginner here
You are dealing with a curve object. Curve objects are different than mehses. You cannot add faces to curves.

You can convert them to a mesh as stated on the other answser. but you can choose to keep them as curves.

To fill, just convert them to a 2d curve and select "both" as the Fill mode.


If you need more concentric rings, just duplicate one of the rings and resize.



If you must convert to mesh, then press Alt C in edit Mode, select convert curve to mesh. Enter edit mode, select all vertices and do "bridge edge loops"