Adding lights to ceiling fan.
There will be a blue and a white wire, capped off, in the housing for your light kit.
The question is, did they hook up the blue wire in the ceiling j box?
If they did, is it on a seperate switch?
Take the canopy off and see what the wiring looks like
If there is only a black and a white wire, the light will only work when the wall switch is turned on and you will have to individually control the fan and light via the pull chains.
If there are more house wires in the jb, describe them for more options.
Typically on a fan, the black goes to the fan motor, the blue to the light kit. The white wire is your neutral. Both the motor and light use the same neutral.