If you are trying to put an aftermarket radio in, identify the 8 speaker wires. Front left, right, rear left, right. Take the radio harness and attach the speaker wires appropriately...there usually is even a diagram printed on the radio or instructions saying which colors are which speakers. You can probably find out online what the colors are for the speakers. Then find your always on battery power for the clock and memory, the ignition on for turning the radio on, antenna wire and hook everything up.
Otherwise, it sounds like you may need to either get someone to help or take it to Best Buy or something.