Opaque NavBar Overlapping H1 and content - html

Question

Ok so figured out the first problem.... now my navbar brand isn't expanding. It seems to be stuck at one size and its added a scroll bar to accommodate. How to I get the whole navbar to move over for the brand?
.navbar {
position: relative;
display:inline-block;
overflow: auto;
background: #f4f4f4;
opacity: .6;
width: 100%;
padding: 5px 8px;
z-index: 9999;}
.navbar-brand {
color:black;
font-weight: bold;
font-size: 300%;}
.navbar a {
float: left;
display: block;
text-align: center;
overflow: auto;
padding: 5px 8px;}
.navbar a:hover{
background-color:#ede2d4;}
<nav class="navbar navbar-expand-lg navbar-light fixed-top justify-content-between">
<div class="container-fluid">
<a class="navbar-brand" href="#">Hello</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav mr-auto">
<li class="nav-item active">
<a class="nav-link" href="index.html">Home <span class="sr-only">(current)</span></a></li>
<li class="nav-item">
<a class="nav-link" href="facts.html">Facts</a></li>
<li class="nav-item">
<a class="nav-link" href="chart.html">Chart</a></li>
<li class="nav-item">
<a class="nav-link" href="video.html">Video</a></li>
<li class="nav-item">
<a class="nav-link" href="jokes.html">Jokes</a></li>
</ul>
<div>
<form class="navbar-form navbar-left form-inline">
<input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
<button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
</form>
</div>
</div>
</div>
</nav>
<h1>Testing Page </h1>

Answer 1

It could easily be because you have fixed-top on the first line of your <nav>. That is absolutely fine but the very next item beneath the Nav ... Which is your <h1>... That might now need margin-top the same height in pixels as the navbar (even a few more pixels wouldn't hurt).
Do you see what's happening? fixed-top is letting the content flood underneath the navbar, adding margin to the top of <h1> will bring it all back down the page a little.
<h1 style="margin-top:50px">Testing Page</h1>
Alternatively add margin-bottom to the Navbar.
There also seems to be a stray </header> closing tag immediately after the Nav