Creating user accounts javascript and API's

Question

I recently started learning about API's and how to get and post data to an API.

So for example I have a sign up form on my site:

        <form ng-submit="submit()">
        <p>Name: <input ng-model="person.name"></p>
        <p>Password: <input ng-model="person.password"></p>
        <p><button>Add</button></p>
        </form>

Which when submitted Posts data to a JSON API.

  var myApp = angular.module('myApp', []);
  myApp.controller('PeopleController', function ($scope, $http) {

  var url = 'https://something.com/users.json';

  $http.get(url).success(function(a) {
    console.log(a);
    $scope.people = a;
  });

  $scope.submit = function() {
    $http.post(url, $scope.person)
   .success(function(data, status, headers, config) {
   })
    .error(function(data, status, headers, config) { 
   });

    }});

The API looks like this:

   {
      "people" : [
    {"name": "Charles Babbage", "password": abc1791},
    {"name": "Tim Berners-Lee", "password": cde1955},
    {"name": "George Boole", "password": efg1815}
    ]
  }

Now I am aware Im missing a lot of stuff like a database such as mongoDB and few other things and this is example is too simple.

But how do I use this information from my API to create user accounts. So if Charles Babbage Signs-in he sees his personal (very basic) profile where he can edit is name and password and then signs out. I am aware I am missing key things such as Authentication and maybe even sessions but I want to take this step by step.

I thank you in advance for any help or advice.

Regards,