A Beginner Question - Function Switcher including LED, RGB

So I have a 2 buttons, 8 leds and a 1 rgb

So the button 1 function it serves as the switcher it allows me to perform various action whenever i press it then the 8 leds will serve as the function indicator whenever I press the button 1 the led will light up and it means the function is working. The Button 2 serves as the function enabler so whenever I push it it will perform the function of the rgb led light

So example I have an eight functions Function 1: Turn on/off RED light
Function 2: Increase RED light brightness by 5; if already at 255, reset at 0
Function 3: Turn on/off GREEN light
Function 4: Increase GREEN light brightness by 5; if already at 255, reset at 0
Function 5: Turn on/off BLUE light
Function 6: Increase BLUE light brightness by 5; if already at 255, reset at 0
Function 7: Turn on ALL lights, all brightness to 255
Function 8: Turn off ALL lights, all brightness to 0

Btw when I start the device the RGB will not be activated.

My question is how am I going to start it?

As of now I've already done when I press the Button 1 it will light the led light indicatior.

const int red = 5;


int function = 0; //Function




void setup() {
  pinMode(2,INPUT);
  pinMode(3,INPUT);
  pinMode(red, OUTPUT);
  for (int i =11; i<=18; i++) {
    pinMode(i, OUTPUT);
  }
  
}

int b1, b2; //Buttons
int dir =0; 
int light =11;

void loop() {
  b1 = digitalRead(2);
  b2 = digitalRead(3);

  if (b1 == HIGH) {
    dir = 2;
  }  else {
    dir = 0;
  }
   digitalWrite(light, LOW); 
    
  if(dir==2 && light < 18) { 
    light++; 
  } 

  digitalWrite(light, HIGH); 
  delay(200); 
}