The blue wire coming from the battery will be the power, or 12v+ you need to connect this to the amp's Power or 12v+
now the white wire that comes from somewhere will be the REM or the little thin wire? ok.. you need to connect that to the Amp's :REM"
thats the one who will signal the amp to turn on..
and for the Ground wire or "GND" you need to get a Wire and tap it on the Car's Body, Somewhere near where you can see a Screw or a bolt. you can just tap it there. the car's whole body (metal Parts) has a ground running on it.
ok?