"Umm you don't know what a FPGA is, and now you need to learn programming FPGA's and make a project in one week??? Wow
My thoughts exactly. It is like you don't know how to swim, yet they are asking you to participate in the swimming championship finals in less than a week.
The question about the flip-flop: I don't understand the relationship to the project at hand, but I still can provide an answer; the simplest flip flop is the "D" type flip flop.
Actually that may not be that difficult. If he only wants you to DESIGN it and not actually IMPLEMENT it then should be fairly easy; just get any old circuit for multiplexing six 7-seg displays and replace the control logic with an FPGA. The FPGA contents will basically just be a bunch of counters and a shift register for multiplexing the displays.
I work extensively with FPGA's and I always have extream difficulty explaining exactly what they are to non-technical people. The very idea that you can take a device and make it into virtually anything you want seems almost mystical!