Button State save, 2 buttons?

So i have done some editing to that one now where do I Put my Keystrokes in at?
I am still very new to programming. Thanks!!

const byte 3 = A1;
const byte 5 = A2;
unsigned long waitStart;
unsigned long currentMillis;
unsigned long period = 15000;

const byte waitingForEitherButton = 0;
const byte waitingForButton2 = 1;
const byte waitingForButton1 = 2;
const byte bothButtonsPressed = 3;

byte currentState = waitingForEitherButton;

void setup()
{
  pinMode(9, INPUT_PULLUP);
  pinMode(5, INPUT_PULLUP);
  pinMode(3, INPUT_PULLUP);
  Keyboard.begin();
  digitalWrite(9, HIGH);
  digitalWrite(5, HIGH);
  digitalWrite(3, HIGH);
  Serial.begin(115200);
  pinMode(3, INPUT_PULLUP);
  pinMode(5, INPUT_PULLUP);
  
}

void loop()
{
  currentMillis = millis();
  switch (currentState)
  {
    case waitingForEitherButton:
      if (digitalRead(3) == LOW)
      {
        currentState =  waitingForButton2;
        waitStart = currentMillis;
        
      }
      if (digitalRead(5) == LOW)
      {
        currentState =  waitingForButton1;
        waitStart = currentMillis;
        
      }
      break;
      //
    case waitingForButton2:
      if (currentMillis - waitStart >= period)
      {
        currentState =  waitingForEitherButton;
        
      }
      if (digitalRead(5) == LOW)
      {
        currentState = bothButtonsPressed;
      }
      break;
      //
    case waitingForButton1:
      if (currentMillis - waitStart >= period)
      {
        currentState =  waitingForEitherButton; //waiting
        
      }
      if (digitalRead(3) == LOW)
      {
        currentState = bothButtonsPressed;
      }
      break;
      //
    case bothButtonsPressed:
     
      delay(2000);    //naughty, but easy
      
      currentState = waitingForEitherButton;
      break;
  }
}