What I would do for now is just unplug the amp from the battery. You wire the amp using phono wires (red and white) which easy easy and can be ignored. You will wire the parcel shelf and door speakers using the white, purple ect. Now that those can all be ignored focus on your remaining wires. There should be 4 and have there own pin on the head unit. Ou will need a constant live, a switch live and an earth, that is all. The blue wire can be ignored but is sometimes used to add a aerial booster.