designing of power amplifier driven by a preamplifier with darlington transistors

am building the above for my school project and i have no idea of where to start i.e designing of power amplifier driven by a preamplifier with normal complementarty darlington power transistors to test on the darlingtons transistors sensitivity gain bandwidth input impedance.....

You don't use darlingtons in a preamp, there would be no point - you're wanting voltage gain more than current gain.

Where you use darlingtons is for the output transistors, simply to replace the descrete darlingtons (or other type) used.