Removing things is often a key part of customizing a theme.
This box represents our beginning. In this scenario, I'm happy to have this descriptive text but I'd like to get rid of the header element above.
Below are some ways we might make this header element disappear. If you're not sure how to figure out what an element is named, check out the "what's my name?" page.
You can edit the CSS by clicking on the elements and editing it live if you want.
In this case, we'll use display: none; and target the element by ID. Notice that the element AND the space it occupied is removed entirely.
Another option is to set the opacity: 0;. Note that the space the words occupied remains when we do it this way.
Clicking the button below sets the opacity to .5.
And yet another way is to set the font color color: #fff; to the same color as the background. I can't think of a great reason to follow this path but sometimes it's worth seeing other options as it keeps your thinking open.