Having given the boundaries sensible names, you can now set the boundary types. Select the Symmetry_plane1 node.
In the Properties window, set Type to Symmetry Plane. The boundary node icon will change to reflect the new type.
Using the same technique, change Symmetry_plane2 to Symmetry Plane. For compressible flows the most appropriate inflow and outflow types are stagnation inlet and pressure outlet. So change the type of the Inlet boundary to Stagnation Inlet and the type of the Pressure boundary to Pressure Outlet.
The Slip_wall and Inner_wall boundaries retain the default Wall type. Slip walls are boundary conditions and are set up later.
Save the simulation by clicking on the 
(Save) button.