What would i change about this diagram to power and regulate this motor to make this a working model
If you change the battery to 12 volts and connect the wiper arm of the potentiometer to the side of the potentiometer that is connected to the motor, it can be used to adjust the motor speed. The motor speed will change if the load torque changes, but that may be acceptable. The potentiometer needs to be rated for at least 5 watts or at least 0.3 amps. If you don't reduce the battery voltage, the 50 ohms rheostat in series will burn up close to half the power and provide a speed range from a little below the motor's maximum rated speed to more than 50% above maximum speed. A 5-watt potentiometer would run quite warm with a 12 volt battery and too hot with 18 to 20 volts.