The serial number can be found in the back of the device, you'll recognize it because it is a 14-digit number. You can also find it on the packaging.

As a general rule you can find the model in the back of your device. It also can be found in the packaging and in the user manual.

The file with the instructions may be in PDF format and probably you don't have an appropriate program to open it. This file format can be opened with Adobe Acrobat Reader (colocar link).