Can't get node express server to run

I have followed a few tutorials on how to get this setup thinking I wasn't getting it but no matter what I try I can't get the server to run.

In it's basic form I just used the express-generator node package to run

express backend

and I get all the files that it looks like I should including an app.js (by the way I'm using the latest stable versions as installed yesterday) when I try to run

node app
node app.js

or

node ./bin/www

(I've seen that somewhere else as well) I can't get the server to run. Running the first two just returns the console and nothing happens, running .bin/www looks like it tries to run something but it just sits and nothing happens.

in bin/www I see the actual script to run the server with the port and all, so I'm assuming that's where I need to be looking.

If you need it for reference this is the contents of app.js generated by the express generator

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var routes = require('./routes/index');
var users = require('./routes/users');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', routes);
app.use('/users', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
    var err = new Error('Not Found');
    err.status = 404;
    next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
    app.use(function(err, req, res, next) {
        res.status(err.status || 500);
        res.render('error', {
            message: err.message,
            error: err
        });
    });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
        message: err.message,
        error: {}
    });
});


module.exports = app;

And the bin/www file contains this

#!/usr/bin/env node
var debug = require('debug')('backend');
var app = require('../app');

app.set('port', process.env.PORT || 3000);

var server = app.listen(app.get('port'), function() {
   debug('Express server listening on port ' + server.address().port);
});

UPDATE: I have discovered that running

npm start

is actually starting the server, and going to localhost:3000 shows the default express server running. I was expecting an output per the many tutorials that I was reading (and yes I made sure to find ones on express v4)