Hi I recently installed an amp in the car wired it up and it worked only the back 2 speakers worked so I then tried to connect the front 2, but when I tested it I now only have left rear working and right drivers door working I am an amateur to this it's my first attempt what have I done wrong please anyone help 

I doubt that anybody can help unless you give a lot more detail, such as amplifier make & model, and which wires you connected to which terminals, and what radio you are connecting them to.