Hi there. As I can see from your page. You are missing the id to connect it to your navbar link.
You wrote this for your navbar links:
nav id="nav-bar">
<ul>
<li><a class="nav-link" href="#AboutUs">About Us</a></li>
<li><a class="nav-link" href="#WhatWeDo">What We Do</a></li>
<li><a class="nav-link" href="Gallery">Gallery</a></li>
<li><a class="nav-link" href="#Contact">Contact Us</a></li>
</ul>
</nav>
However for your section, you did not add the id that will properly link it to your navbar links:
<section id="cakeBoss">
<h2>About Us</h2>
<p>The Cake Boss has been in the business of bringing our clients' imagination to life through our cakes and sugar craft designs. Our pioneer Cake Boss Ms. Judy Bunny has been baking and hand crafting beautiful designs since 1998. Its always a pleasure to see a huge smile on the face of every client that works in through our doors.
</p>
<h2>What We Do</h2>
<p>We simply bring to life your imagination through our cakes and sugar craft designs. Our only desire is to ensure that we have a satisfied client every single time.
</p>
</section>
so here you should try to add this code:
> <h2 id="AboutUs"></h2>
> <h2 id="WhatWeDo></h2>
and so on…
Hope this help.
Good Luck!