Mass effect disk installation issues

(side note: proof of the item and the disk are attached to this) Alright so I got this copy of mass effect DVD copy from a garage store and I was trying to install the game, when I put in the code that was labeled inside of the box it said it was incorrect after many times of checking the code and making sure I did not put anything wrong in it it still came out as wrong. I was wondering if there was a method where I can pull the code from somewhere that could be used to activate the installation. Also as I couldn't get the manual I have questions regarding the separat disk that is labled mass effect it claims that it needs the first disk which is labled mass effect one but I am confused with the purpose of the disk as even when I install a program from the disk nothing happens and nothing gets installed. I don't know if the answer is clearly obviouse but it would really help if anyone can instruct me with this.