Understanding Node - Writing Asynchronous code

I am making my first steps on NodeJs. I came from Java world, and my head stuck when writing asynchronous code. I have read a lot about asynchronous flow, when dealing with I/O block operations but i don't really know how to solve this issue.

I am doing a google API call, when i create an instance of "point" object to retrieve longitude and latitude of the point.

In my "app.js" flow, i invoke a function that inside of it call another function that requires that longitude and latitude. As you see, at this point google API call didn't come back and its retrieve "undefined".

How to think this problem in a "Asynchronous way"?

//app.js

const express = require('express');
const POI = require('./models/poi');
var app = express ();

app.get('/', (req, res) => {

    var poiA = new POI(19146, "Saraza", 2, 3);
    var poiB = new POI(19146, "Saraza", 4, 5);


    console.log(poiA.estaAXMetrosDeOtroPoi(poiB, 10));

});

app.listen(3000);

const Point = require('./point');

function POI (direccion, nombre) {

    var self = this;

    var direction = direccion;

    var nombre = nombre;

    var point = new Point(direccion);


    self.getPoint = () => {
        return point;
    };

    self.estaAXMetrosDeOtroPoi = (otroPoi, distancia) => {
        let poiDistance = point.distanceBetweenPOIsCoords(point, otroPoi.getPoint());
        return (distancia >= poiDistance);
    };

}

module.exports = POI;

var geolib = require('geolib');
var geoCode = require('../services/geoCode');

function Point (direccion){

    var self = this;

    self.latitude;
    self.longitude;

    
    
    self.geoLocalizate =  (direccion) => {
        
        //Here i am making google API call
        
        geoCode.geocodeAddress(direccion, (errorMessage, results) => {
            if(errorMessage){
                self.latitude = null;
                self.longitude = null;
            }else{
                self.latitude = results.latitude;
                self.longitude = results.longitude;
            }
        });

    };

    self.geoLocalizate(direccion);

    self.getCoord = () => {
        return {"latitude": self.latitude, "longitude":                                         self.longitude};
    };
    
    //Function throwing error, becouse of latitude, longitude "Undefined"
    
    self.distanceBetweenPOIsCoords = (pointA, pointB) => {
        let coordA = pointA.getCoord();
        let coordB = pointB.getCoord();
        return geolib.getDistance(coordA, coordB);
    };


};

via Nicolas Taboada