Q:

Button that shows a modal that include page inside of it

How can i type a JQuery or Ajax script that When i click on (for example) <button>WORLDS</button> shows a modal in the same page that include a page out of it. 

A:

Although you didn't provided any code, I will answer your question, hoping it will help you.  You can use an iframe for the external page part:

$('button').on('click', function() {
  $('.overlay, .popup').fadeIn();
});
$('.overlay').on('click', function() {
  $('.overlay, .popup').fadeOut();
});
.overlay {
  background: rgba(0, 0, 0, 0.7);
  position: fixed;
  top: 0;
  left: 0;
  height: 100%;
  width: 100%;
  display: none;
}
.popup {
  background: #fff;
  padding: 20px 20px;
  box-sizing: border-box;
  max-width: 300px;
  width: 100%;
  margin: 50px auto 0px auto;
}
iframe {
  width: 100%;
  height: auto;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button>WORLDS</button>
<div class='overlay'>
  <div class='popup'>
    <iframe width='' src="http://stackoverflow.com/"></iframe>
  </div>
</div>

