Comment pourrais-je déplacer un div sous un autre div et avoir toujours le div supérieur "position: fixed"?

<div id="header">
		<ul id="name">
			<li><a href="#">DevWeb Web Development</a></li>
		</ul>
		<ul id="nav">
			<li><a href="#">About Us</a></li>
			<li><a href="#">Contact Us</a></li>
			<li><a href="#">Gallery</a></li>
		</ul>
	</div>
	<br>
	<div class="everything">
		<div id="webInfo">
			<img src="imgs\personWebsite.png" alt="If you see this message please E-Mail the developer at oof" style="top: 50;">
		</div>
		<br>
		<br>
		<div id="missionStatement">
			<p id="ourStatement"><u>Mission Statement</u></p> 
			<p style="font-size: 0.5px;">-</p>
			<blockquote>Our goal is to bring you the best customer service and web design that will ever meet your eyes. And we strive to bring you just that. Because when it comes to the front of your business, you want the best quality with the customer support that you need to keep it running. And that's the way that DevWeb Web Development does things.</blockquote>
		</div>
		<div id="wantWebsite">
			<img src="imgs\finger.png" alt="If you see this message please E-Mail the developer at oof" style="max-width: 100%;">
			<p id="schedule"><a href="#">Schedule <strong>YOUR</strong> appointment <strong>TODAY</strong></a></p>
		</div>
	</div>

#header {
  background: white;
  color: black;
  text-align: center; 
  font-weight: bold; 
  position: fixed;
  top: 0; 
  width: 100%;
  border-bottom: 2.5px solid black;
  left: 0;
  position: relative;
}

#nav {
text-align: right;
padding: 0px 20px;
font-size: 40px;
transition: 0.2s;
font-family: "Source Sans Pro", sans-serif;
}

#name {
text-align: left;
padding: 0px 20px;
font-size: 50px;
transition: 0.2s;
font-family: "Montserrat", sans-serif;
color: black;
}

#ourStatement {
font-size: 39.06px;
}

#skyLimit {
border-bottom: 1px;
}

#everything {
position: relative;
}

li a {
color: black;
text-align: center;
padding: 0px 20px;
text-decoration: none;
}

ul {
list-style-type: none;
}

li {
display: inline;
}

a:hover {
text-decoration: underline;
}

a {
text-decoration: none;
}

#missionStatement {
text-align: center;
font-family: "Arial";
}

blockquote {
font-size: 31.25px;
border-left: 10px solid gray;
border-radius: 5px;
}

img {
max-width: 100%;
} 

#schedule {
font-family: "Arial";
font-size: 50px;
color: black;
text-align: center;
}

a:visited {
color: black;
text-decoration: none;
}

window.onscroll = function() {scrollFunction()};

function scrollFunction() {
  if (document.body.scrollTop > 50 || document.documentElement.scrollTop > 50) {
    document.getElementById("nav").style.fontSize = "30px";
    document.getElementById("name").style.fontSize = "40px";
    document.getElementById("header").style.backgroundColor = "#f2f2f2";

  } else {
    document.getElementById("nav").style.fontSize = "40px";
    document.getElementById("name").style.fontSize = "50px";
    document.getElementById("header").style.backgroundColor = "white";
  }
}