24 second shot clock

Please Help!!

I started out this code to initially display 24 seconds. However, im stuck to this .. How could I start the loop to start the countdown when a starStopButton is pressed and reset to 24 again when restButton is pressed. Thanks

const int clockPin = 3;
const int dataPin = 2;
const int startStopButton = 4;
const int resetButton = 5;

static byte displayDigit[10]= {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};




void setup()
{
  Serial.begin(9600);
   pinMode(clockPin, OUTPUT);
   pinMode(dataPin, OUTPUT);
   pinMode(startStopButton, INPUT);
   pinMode(resetButton, INPUT);
   initDisplay();
 }

void loop()
{
 
 }

 void initDisplay()

 {
   shiftOut(dataPin,clockPin,MSBFIRST,0x66);
   shiftOut(dataPin,clockPin,MSBFIRST,0x5b);
 }

I don't see anything in your code to detect button presses.

This is not rocket science. Plenty of tutorial online.