Hi Larry,
This is my first attempt at helping out on the community forums so please bear with me!
Your navigation menu is at the top of the page in the theme. Moving it in CSS is possible, though it's a bit "hacky". #top { position: absolute; } is the first step. This makes the div that contains your menu a bit more 'independent' - you can move it down from the top of the page without subsequently moving everything underneath it.
You'd need to push it down from the top of the page by the height of the blue header bar. If your header is 100px high, for example, you could use either of these (you don't need to use both):
#top { margin-top: 100px; top: 100px; }
It's up to you whether you use margin-top or just top, it's up to you.
Moving the top div down will place it over your header or content. To create a blank space for the top bar to be positioned over, try giving the header some margin on the bottom of the same height as the navigation. Assuming it's 25px, it would be:
#header { margin-bottom: 25px; }
This margin would push the content down and create an area 25px high that your navigation (#top) can sit over.
Hope that helps.