Arduino LED Fire Simulation

Ok so I'm trying to make a small 10 led display simulating red fire. I have wired up the ten leds to pins 2-11 and have put everything on a breadboard in 2x5 rectangle and want to have one row consistently flash in a pattern using

digitalWrite(2, HIGH);
digitalWrite(5, LOW);
delay(100);
digitalWrite(3, HIGH);
digitalWrite(6, LOW);
delay(100);
digitalWrite(4, HIGH);
digitalWrite(2, LOW);
delay(100);
digitalWrite(5, HIGH);
digitalWrite(3, LOW);
delay(100);
digitalWrite(6, HIGH);
digitalWrite(4, LOW);
delay(100);

and have leds 7-11 doing a random repeating order at the same time. I'm not sure how make it random in the first place or get them to go at the same time.

any ideas or explanations would be much appreciated. Also everything will be looping as long as a button is held down not sure how to code that either. So yah.

Thanks in advance.

So when 2 lights, it 'ignites' the one next to it after a short delay. Then after some longer delay, 2 is "burned out" and doesn't light again until the pattern repeats?

Look at the Blink Without Delay example.

Also look into LED driver chips. 10 LEDs all on at the same time will easily draw too much current from the Arduino. As you scale up to larger LEDs and larger numbers of them, a dedicated driver like a MAX6971 allows you to control 16 LEDs with 3 Arduino outputs and it manages the current through each individual LED without lots of resistors. You can also daisy-chain the drivers so the next 16 LEDs use no additional Arduino pins.