Freezer fan is noisey and can t find serial number

The number you will need is the model number. On side by side models there are a few places to look. 1- inside fridge on right or left wall. 2- Open fridge door and look up near the top front lip. 3- Open both doors and look on body of fridge under the doors. 4- Fridge door sometimes there is a sticker right when you open. Mostly you are looking for a silver sticker or silver plate. It gives you a model number and serial number. If you need further assistance please mail me back.