Oiling the motor externally is unlikely to achieve anything. The axle will turn in factory lubricated ball bearings, sealed to keep out dirt and water so any externally applied oil will not penetrate. Motors often sound "creaky" because the power is applied as a series of rapid puses which can cause vibration, this is normal and nothing to worry about. Other noises can be caused by the motors internal gears which may get quiter as the motor runs in, again nothing to worry about.
The best thing is to leave it alone for now, if it doesn't get worse then the chances are all is OK.