In navigation menu if you wanna add the page link you can extend the nav-item is given below from navbar-nav. For add dropdown list in navigation menu add dropdown-menu class and add dropdown-item under the dropdown-menu. An example is given below.
<ul class="navbar-nav">
<li class="nav-item dropdown active dropdown-slide">
<a class="nav-link" href="#" data-toggle="dropdown">Link with dropdown
<span><i class="tf-ion-ios-arrow-down"></i></span>
</a>
<!– Dropdown list –>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">dropdown one</a>
<a class="dropdown-item" href="#">dropdown two</a>
<a class="dropdown-item" href="#">dropdown three</a>
</div>
</li>
<li class="nav-item">
<a class="nav-link" href="#">without dropdown</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">without dropdown</a>
</li>
</ul>