2.0l wiring

[corsagaz]

ive fitted my c20ne from a cavalier to my corsa b along with the wiring from the cavalier. however i am now at the point of connecting the wires and to be honest dnt kno where to start. on the corsa wiring there are two red and blue wires however on the cavalier side there is only one that is expose do i join them to the same wire or do i splice them onto another????????????? also there is a red wire and a blue wire on the corsa side
i am told the blue is for the temp gauge on dash but on the cavalier wiring there is no blue
the red i have no idea do i leave this or do i connect to a switch live helllllllllllllllllllllllppppppppppppp someone please