Modern notebook CPUs run very cool, and only generate a lot of heat when they are stressed. It's very possiblypossible that your fan will never come on during light use.
My guess is that if you use an intensive application the laptop fan will come on eventually.
You can download a programs like Prime95 to stress your CPU, and a program like CoreTemp to check temperatures.
Anything Below 80C is safe. The CPU has a safety to turn itself off when it reaches about 90C-95C.
ThenThe fan is there to give the user the choice - some prefer a cooler keyboard to work with.