<header>
  <h1>My Site Name</h1>
  <nav>
    <ul>
      <li><a href="#0">Navigation link 1</a></li>
      <li><a href="#0">Navigation link 2</a></li>
      <li><a href="#0">Navigation link 3</a></li>
      <li><a href="#0">Navigation link 4</a></li>
      <li><a href="#0">Navigation link 5</a></li>
      <li><a href="#0">Navigation link 6</a></li>
    </ul>
  </nav>
</header>

* {
  box-sizing: border-box;
}

body {
  background: #FFB74D;
}

a {
  color: black;
}

header {
  display: flex;
  justify-content: space-between;
  padding: 20px;
}

h1 {
  flex: 1 0 auto;
}

ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
}

a {
  display: block;
  padding: 20px;
  text-align: center;
}