You can also use Inspect Element in your browser to find stuff!
Right click on the page, and select Inspect Element, it's the option on the bottom. In the Element tab (it's the default one so no need to change) you can hover your pointer over the HTML lines, which will highlight that part of the page. You'll find the name of the class in the code, where it says class="some-name"
:D For example <div class="cool-name">Weewoo</div>
You'll need to click the arrow on the left of the line of code to see the elements under it, btw