arduino uno and L293D IC help....noob here

Hi Guys i was able to make it work now there is one thing i want to ask.because i am using separate power to arduino uno and the 12v motor..is there a way to power them using only one source of power...

And because of a little knowledge on arduino and electronics i also purchased an cytron motor driver shield md10.. can this replace the l293d h-bridge circuit.. or this is useless for what i want??

basically i only need to control the direction and speed of my DC motor..