Code to make stop watch with I2C?

Using Arduino Displays
1

hey guys im new here, i want to ask about code that i find in the internet.
its the first time i use i2c with lcd so i didnt really get how it work....#pleasehelp :sob:

this is the code:

#include <I2C.h>

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x3F ,2,1,0,4,5,6,7,3, POSITIVE);

unsigned long mulai, selesai, dataStopWatch;
int i=0;
int fPaus = 0;
long lastButton = 0;
long delayAntiBouncing = 50;
long dataPaus = 0;

void setup(){
pinMode(A0,INPUT);
pinMode(A1,INPUT);
digitalWrite(A0,1);
digitalWrite(A1,1);
lcd.begin(16, 2);

lcd.setCursor(0, 0);
lcd.print("Arduino");
lcd.setCursor(0, 1);
lcd.print(" StopWatch");
delay(2000);
lcd.clear();
lcd.print(" Tekan Tombol");
lcd.setCursor(0, 1);
lcd.print(" Start / Stop");
}

void loop(){
if (digitalRead(A0)==0){
if ((millis() - lastButton) > delayAntiBouncing){
if (i==0){
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Start Timer");
mulai = millis();
fPaus = 0;
}
else if (i==1){
lcd.setCursor(0, 0);
lcd.print("Stop Timer ");
dataPaus = dataStopWatch;
fPaus = 1;
}
i =!i;
}
lastButton = millis();
}
else if (digitalRead(A1)==0 && fPaus == 1){
dataStopWatch = 0;
dataPaus = 0;
lcd.clear();
lcd.print("Reset Stopwatch");
lcd.setCursor(0, 1);
lcd.print("0:0:0.0");
delay(2000);
lcd.clear();
lcd.print(" Tekan Tombol");
lcd.setCursor(0, 1);
lcd.print(" Start / Stop");
}

if (i==1){
selesai = millis();
float jam, menit, detik, miliDetik; //hour,minute,second
unsigned long over;

// MATH time!!!
dataStopWatch = selesai - mulai;
dataStopWatch = dataPaus + dataStopWatch;

jam = int(dataStopWatch / 3600000);
over = dataStopWatch % 3600000;
menit = int(over / 60000);
over = over % 60000;
detik = int(over / 1000);
miliDetik = over % 1000;

lcd.setCursor(0, 1);
lcd.print(jam, 0); //hour
lcd.print(":");
lcd.print(menit, 0); //minute
lcd.print(":");
lcd.print(detik, 0); //second
lcd.print(".");
if (jam < 10){
lcd.print(miliDetik, 0); //milisecond
lcd.print(" ");
}
}
}

im sorry theres still indonesia language in there, any suggestion will help thanks.
and if you know how use it in proteus please tell me how to connect between ardino i2c and lcd (16x2).

thank you