Open up your Arduino IDE
Connecting the Arduino to the computer USB
Tools--board,choose your Arduino
Than you can see this code
You can Turn the LED on(HIGH),turn the LED off(LOW)
And wait for a second(delay(1000)),if you want two second,Change 1000 to 2000.Is that simple?
Check out our Arduino,yellow LED Blinking.Congratulations,you get ready be a maker.