if you purchased your product from these firms like Amazon, you "only" get a code with which you can request a serial number from Adobe. Please have a look at Find your serial number quickly >>> (Start here: How did you purchase your product?)
The following part, so I just see at least, ceased to exist on my Adobe website, everything takes place in the link from above. I leave it as an info yet, it might still fit for you. For this purpose, please click your way through to your Adobe Store and find the button "Get Serial Number". Fill in the form and after a while you will get the real serial number.