Front Layout?

fonts can be altered through style.css. use firefox browser with the firebug addon. This tool will become extremely valuable when learning to theme drupal. once you find the css that is being called, find it in your style.css file and alter as necessary.

Actually, all you need to do to change the text your referring to on the front page is go to Administer :: Site building :: Blocks and click configure next to the "header text" block. Likewise the configure the "header images" block to change the image.