The PIC18F4550 can only work as a USB device - that means that it can only be connected to a USB host like a PC. You cannot connect two PIC18s to one another via USB.
Only the PIC24s and PIC32s have a USB host capability. To do what you describe, you would need to take one of these controllers, but they don't have internal EEPROM.
I have no experience with the CCS USB stack. Microchip offers a free USB stack as part of their "Application Framework" available here: http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2680&dDocName=en547784
When installed, you will find lots of functional MPLAB IDE based projects for the PIC18F4550. I would suggest starting with the 'CDC Class'. This is the class under USB that appears as a 'COM' port, and can be treated in the same way on the PC side as an old, real hardware COM port by most terminal programs (teraTerm, Hyperterminal etc.)
Using the CDC class, you can simply output test strings over the USB interface, and then display them using the above mentioned terminal programs. This eases you into getting USB up and running, without having to worry about writing PC code or your own USB drivers.