Bootstrap 4 default tab-pane active fade in not working

You just need to add below elements and bootstrap css.

<!-- 1. BOOTSTRAP v4.0.0         CSS !-->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<!-- 2. GOOGLE JQUERY JS v3.2.1  JS !-->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<!-- 3. BOOTSTRAP v4.0.0         JS !-->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>

<ul class="nav nav-tabs" id="myTab" role="tablist">
  <li class="nav-item">
    <a class="nav-link active" id="home-tab" data-toggle="tab" href="#home" role="tab" aria-controls="home" aria-selected="true">Home</a>
  </li>
  <li class="nav-item">
    <a class="nav-link" id="profile-tab" data-toggle="tab" href="#profile" role="tab" aria-controls="profile" aria-selected="false">Profile</a>
  </li>
  <li class="nav-item">
    <a class="nav-link" id="contact-tab" data-toggle="tab" href="#contact" role="tab" aria-controls="contact" aria-selected="false">Contact</a>
  </li>
</ul>
<div class="tab-content" id="myTabContent">
  <div class="tab-pane fade show active" id="home" role="tabpanel" aria-labelledby="home-tab"><p>Raw denim you probably haven't heard of them jean shorts Austin. Nesciunt tofu stumptown aliqua, retro synth master cleanse. Mustache cliche tempor, williamsburg carles vegan helvetica. Reprehenderit butcher retro keffiyeh dreamcatcher synth. Cosby sweater eu banh mi, qui irure terry richardson ex squid. Aliquip placeat salvia cillum iphone. Seitan aliquip quis cardigan american apparel, butcher voluptate nisi qui.</p></div>
  <div class="tab-pane fade" id="profile" role="tabpanel" aria-labelledby="profile-tab"><p>Raw denim you probably haven't heard of them jean shorts Austin. Nesciunt tofu stumptown aliqua, retro synth master cleanse. Mustache cliche tempor, williamsburg carles vegan helvetica. Reprehenderit butcher retro keffiyeh dreamcatcher synth. Cosby sweater eu banh mi, qui irure terry richardson ex squid. Aliquip placeat salvia cillum iphone. Seitan aliquip quis cardigan american apparel, butcher voluptate nisi qui.</p></div>
  <div class="tab-pane fade" id="contact" role="tabpanel" aria-labelledby="contact-tab"><p>Raw denim you probably haven't heard of them jean shorts Austin. Nesciunt tofu stumptown aliqua, retro synth master cleanse. Mustache cliche tempor, williamsburg carles vegan helvetica. Reprehenderit butcher retro keffiyeh dreamcatcher synth. Cosby sweater eu banh mi, qui irure terry richardson ex squid. Aliquip placeat salvia cillum iphone. Seitan aliquip quis cardigan american apparel, butcher voluptate nisi qui.</p></div>
</div>

USE fade show instead of fade in in the tab-content classes

Reference https://getbootstrap.com/docs/4.0/components/navs/?#javascript-behavior

This is the way of solving it on bootstrap 4. But in bootstrap 3, your code should be working.

Related question for bootstrap 3. Bootstrap tab - active class not working on page loading

<!-- 1. BOOTSTRAP v4.0.0         CSS !-->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<!-- 2. GOOGLE JQUERY JS v3.2.1  JS !-->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<!-- 3. BOOTSTRAP v4.0.0         JS !-->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>

<!-- Toggleable / Dynamic Tabs -->

<nav class="nav nav-tabs nav-justified">
  <a class="nav-item nav-link active" data-toggle="tab" href="#home">Home</a>
  <a class="nav-item nav-link" data-toggle="tab" href="#menu1">Menu 1</a>
  <a class="nav-item nav-link" data-toggle="tab" href="#menu2">Menu 2</a>
  <a class="nav-item nav-link disabled" data-toggle="tab" href="#menu3">Disabled</a>
</nav>

<div class="tab-content">
  <div id="home" class="tab-pane fade show active">
    <h3>HOME</h3>
    <p>Some content in menu HOME.</p>
  </div>
  <div id="menu1" class="tab-pane fade">
    <h3>Menu 1</h3>
    <p>Some content in menu 1.</p>
  </div>
  <div id="menu2" class="tab-pane fade">
    <h3>Menu 2</h3>
    <p>Some content in menu 2.</p>
  </div>
  <div id="menu3" class="tab-pane fade">
    <h3>Menu 3</h3>
    <p>Some content in menu 3.</p>
  </div>
</div>