Here is the easiest and quickest way to get up and running with an Arduino Due on a Mac.
Step 1: Plug the micro usb to the usb port closest to the DC power supply. This is called the programming port. (ref: https://www.arduino.cc/en/Main/arduinoBoardDue)
Plug the other end into your Mac.
Step 2: Download the Arduino software for Mac at https://www.arduino.cc/en/guide/macOSX
Step 3: You will have to install what is called the Sam Boards Core (32 bit ARM Cortex-M3). Check out this link https://www.arduino.cc/en/Guide/Cores. Basically go to Tools > Board > Boards Manager and select Sam Boards Core (32 bit ARM Cortex-M3) by Arduino.
Step 4: Tell OSX the port to connect to the Arduino. It will be something like /dev/cu.usbmodem1421
Step 5: Open the Blink sketch. Sketch is the equivalent of “code”. This will make the “L” led blink.
Hit the arrow icon to upload to the Arduino.
You should now see the LED blink. Try changing the values to change the blinking speed.