You are trying to mount a DIN sized rectangular face chassis into a space made for a radio with a shaft on each side. I am uncertain if you will ever find a mounting kit for this car, you might have to fabricate something.
As far as the wiring goes, you will need a multimeter. Set it to volts, put the black lead on metal behind dash and check each wire carefully with ignition on and off, lights on and off, etc .. to determine which wire is what.