How arudino execute commands

Main reason why Im interested in this. Im measuring consumption and wattage of blinking led light. So I need average values for current and voltage (like from 5 seconds). So I thought if I make for loop, which will repeat like for milion times it will make average value..

 unsigned long msec = 0;
 float time = 0.0;
int sample = 0;
float totalCharge = 0.0;
float averageAmps = 0.0;
float ampSeconds = 0.0;
float ampHours = 0.0;
float wattHours = 0.0;
float amps = 0.0;
int i,k;
float current1, current2, current;
float wh;
unsigned long previousMillis = 0;  
unsigned long currentMillis;
long interval=1;

void setup() {
  Serial.begin(9600);
}

void loop() {

  int resistance = analogRead(A0);
  float Uresistance = resistance* (5.0 / 1023.0);
    
  int resistancediode = analogRead(A2);
  float Uresistancediode = resistancediode * (5.0 / 1023.0);
  
  float current1=Uresistance/0.47;
   for (long i=0; i <= 1000000; i++){
  current2=current2+current1;
  if (i=1000000) current=current2/1000000;
   }
   


   
  float voltage=Uresistancediode - Uresistance;
  float wattage=current*voltage;
  
   sample = sample + 1;
  msec = millis();
 time = (float) msec / 1000;
totalCharge = totalCharge + current;
averageAmps = totalCharge / sample;
ampSeconds = averageAmps*time;
ampHours = ampSeconds/3600;
float wattSeconds = voltage * ampSeconds;
wattHours = voltage * ampHours;
  
  
 wh=wh + ((wattage*time)/1);
 


 currentMillis = millis();
if(currentMillis - previousMillis > 1000) {
previousMillis = currentMillis;

  Serial.print("Current: ");
  Serial.print(current);
  Serial.println(" A");
  Serial.print("Voltage: ");
    Serial.print(voltage);
    Serial.println(" V");
      Serial.print("Wattage: ");
        Serial.print(wattage);
        Serial.println(" W");
        Serial.print("Consumption: ");
        Serial.print(wh);
        Serial.println(" Ws");
        Serial.print("          ");
        Serial.print(wh/3600);
        Serial.println(" Wh"); 
        Serial.print("Time of run: ");
         Serial.print(time);
        Serial.println(" s");
          Serial.println();
}
}