How to power arduino and a 12v v DC motor using one power source

Hi guys i am very new to this things..I was able to follow a step by step tutorial on controlling a 12V DC Motor speed and direction using Arduino UNO and L293D IC. However i want it to use only one source for power for both because the tutorial i followed is using two source of power one for the Arduino UNO and one for the 12v Motor..

and also for the fact that i don't know what i am doing i think i purchased a wrong part for what i want...i purchased cytron Motor Driver Shield MD10. and i was thinking if this can replace the L293D circuit i made to control the speed and direction of my DC Motor..

this is my setup

That shield looks like a nice and powerful MOSFET H-bridge - but you haven't said what your motor is
(links to datasheet?)

Don't try to power the Arduino from the motor supply if you can help it, most problems with motors
are due to sharing supplies or inadequate motor supply. If you do try to share then you probably
need to add some filtering components and you may need a supply that doesn't droop under twice
the stall current of the motor. (Motors pull twice stall current upon sudden reversal)

this is fpr the DC MOTOr: - Simplifying Digital Making

And Te motor driver shield: - Simplifying Digital Making

USER MANUAL for SHIELD: SHIELD-MD10 User's_Manual - Google Docs

I´m using just one power supply to test some circuits and codes for a DC Motor. There´s no problem for supplying both devices in parallel (Arduino Board and Shield). I mean, take a cable to the de Arduino an another to the shield, both from de power supply(obviously from 12V supply).

I´m not using a shield, I´m just using a Low-Side Mosfet-N Circuit and I have no problem. Even I can regulate the speed of the motor with Arduino PWM.

I see you corrected the wiring error in the Fritzing for pin 9 PWM input. I saw you corrected on your other post too.