You would need to add padding-top to the element after the fixed div to push it down.
JSFIddle Demo
BTW, IDs and classes cannot start with numbers...hence
HTML (partial)
<div id="menu">
<nav>
<p id="menus">
<a class="menusor" href="#1">1</a>
|
<a class="menusor" href="#2">2</a>
</p>
</nav>
</div>
<div id="one"> etc...
CSS (partial)
nav {
text-align:center;
display:inline-block;
background-color:#351b0e;
width:70%;
font-size:1.2em;
padding-left:15%;
padding-right:15%;
position:fixed;
top:0%;
z-index:9999;
margin-bottom:25%;
}
#one {
padding-top:70px; (or some other value)
}