Fine! Now you can find out yourself, which Arduino pins are used by the shields. Obviously many pins are used by both shields, so that you cannot use these shields together.
In detail the WiFi shield uses 7 I/O pins, the motor shield uses 10 pins, and the Uno has 14 digital plus 6 digital/analog pins (20 total). This means that you can use such modules together, but not with the fixed pin assignments of the shields.
The remaining 3 pins don't allow to extend your robot later, with additional sensors etc., so that you should consider to use an Arduino Mega, with many more I/O pins.
In either case you can use only one of the shields as-is, while the other module must be wired to the remaining free pins. The related library also must be modified, to reflect the changed pin numbers. I'd use the WiFi shield as-is, and look for a motor driver board (not shield) that can be connected to arbitrary pins. Modifying the motor driver library should be easy, you only have to replace the #define's for the pins by the new pin numbers.