The wiring on most paddle / ceiling fans id such:
White = Fan and Light neutral or "common"
Black = Fan line voltage or "hot"
Blue = Light line voltage or "hot"
Green = safety ground
If you are replacing an existing light fixture - be sure to replace the ceiling box with one designed for use with a fan - as per electrical code. If the existing box had only 2 wires (or 3 counting the ground) that connected to the old light fixture and it was controlled from a wall switch, the wiring would be fixture white to ceiling white, fixture black and fixture blue to ceiling black (or red) and fixture green to ceiling bare ground or connected to the metal box. This would power both the fan and light whenever the wall switch was on and the pull chains for each were also on. This is also the preferred wiring for replacement of a pull chain type light fixture (no wall switch present).
If there are other wires in the box that previously were not connected to the old light fixture, using a meter or tester - determine if there is constant power between the ceiling white wire and any of the these other wires (test with the wall switch on and off to be sure). If you do have constant power available, you might consider using the wall switch to control only the light, and using the pull chain to operate the fan (or vice-versa). Simply connect the black (for fan) or the blue (for light) to the "constant power on" wire and that part of the fixture will work by pull chain only - regardless of the wall switch position. If the fan can be shut off by the wall switch, it is very important that the wall switch remain a toggle (or on / off switch), do NOT replace with a dimmer type switch.
If you'd prefer to operate the fan and light completely independently of each other - you can purchase a 3rd party fan & light remote control
device for between $30 - $50.
I hope this helps and good luck! Please rate my reply. Thanks!