Header Size & Font

Header box is meant to be over the whole width. So it should not only take half of the screen but the whole.
Font size could be reduced. You need to edit your theme manually.
Best practice is using a child theme.
Within your child style.css you can add something like

.site-intro {font-size: 0.9 em;}

Hi – Thanks for your response! I realize it needs to cover the whole width. I was actually referring to the height. If you pull up the page, you can’t get a view of much of the body of the page. It’s all header. If I reduce the font size as you suggested with the header box height be reduced as well?

@rosecolleran:
Yes it does reduce the height as well.

You may use an developer tool for your browser to test it before (Firebug for firefox or build-in tools of safari or chrome)

The size of fonts should be medium to read easily for others.