How can I color or reduce the size of the news header?

Do you mean this home page area surrounded in red? http://cl.ly/FSbW/o

To change the background color of the top part of the home page in the Structure theme, try this:

#homepagetop {
background: beige;
}

Adjust the color name as necessary.

To reduce the size of the home page area in the Structure theme, you might try shortening up some of the padding and margins like this:

#homepagetop .textbanner {
display: none;
}

#homepagetop {
padding-bottom: 0;
padding-top: 20px;
border-top: 5px solid black;
}

#homepagetop .homewidgets ul li {
margin-bottom: 0;
}

How do I add an image space for my logo?

This depends on the theme you're using, the size of the logo, and where you would like to place the logo on your site.

http://godadago.wordpress.com/ is currently using the Structure theme. Is that your final choice?

Can you please upload your logo image to your media library and provide a link in a reply here?

Where on the page at http://godadago.wordpress.com/ would you like a logo to appear?

Help! how do I add code to css when I do not see any in my css page?

To see the existing CSS for a theme, go to Appearance → Custom Design → CSS and click on the link that says "View the original stylesheet."

my site is http://www.godadago.wordpress.com and I read through the html and css tutorials and am still having an issue...

Any suggestions would be helpful!