simple explanation how to save code that espruino run on start?

hi, I play now a couple hours with save and onInit function and can't run my program when my pico is starting after reset (unplug from usb), is there any simple explanation?
here is the code

function oled(){
 
         g.clear();
         g.setFontVector(28);
         g.drawString("FIRST",0,12);  
         g.flip();
  
  setTimeout(function(){
    nextOne();
    setTimeout(function(){clear();},3000);
    setTimeout(function(){setInterval(data,1­000);},3200);
  },2000); 
}

function nextOne(){
    g.clear();
    g.drawString("NEXT",0,12);
    g.flip();
}

function clear(){ g.clear();g.flip(); }

function data() {
  var bat = analogRead(A5);
  g.clear();
  g.drawString(bat.toFixed(2) + "v",0,0);
  g.flip();
}

function onInit(){
setTimeout(function(){
  oled();
  },2000); 
 // onInit();
}

onInit();

I2C2.setup({scl:B10,sda:B3});
var g = require("SSD1306").connect(I2C2);
  
E.on('init', function() { onInit();  });