If , as it seems , that you have no electronics experience, it might be a good idea to look at some tutorials or schematics of similar setups.
Obviously the motor isn't going to be powered by the arduino +5V onboard regulator so you must have misinterpreted something you read that referred to the motor being "driven" and thought that meant "powered" , which it doesn't. "Driven" is a reference to the control signals that "drive" the motor in the sense that the PWM signal determines the motor speed by varying the duty cycle of the signal connected to the ENable pin of the L298 chip. The photo clearly shows three pins for the power connection;
a GND, Vcc (that's Motor Power to you) and +5V (that's L298 logic power to you). Read the L298 datasheet and you see the chip requires two different voltages : +5V for the logic and whatever voltage you are using to drive the motor. It also requires Direction
pin inputs. I suggest you do not apply power to anything until you thoroughly understand what you are doing. One wrong move and your chip (and maybe the arduino) will be toast.