Note that the header background has been a boring gray. You can change that to something more meaningful or colorful. If you're doing a course on Marcel Proust, you could have a picture or painting of the man or a picture of one of his books. I put a photo of my dog, Yeti, on this page because who doesn't like dogs?
To change the background, put your cursor in the lower left corner of the header and click Change Image. A box will pop up asking whether you want to Upload a photo from your hard drive, or Select an Image from online or other sources. Go ahead and click around to find whatever image you think might be colorful and appropriate
The Search function gives you the ability to search for images which can be freely used on your web site without fear of copyright infringement. The Upload function allows you to insert an image that you have saved on your computer.
In the lower left corner of the header there is also a button for Header Type. Go ahead and click that; you can change the size of the background photo in the header. Cover makes the photo very large. Large Banner is an intermediate size. Banner makes the smallest sized photo and Title Only does what it says. Note that the top and bottom of the photo might be cropped off, depending upon the width of the browser window and the dimensions of the photo. Sometimes you might have to crop the photo yourself before adding it in if you want to make it look right. But go ahead and play!