You can read some of the tutorials on StudioPress about adding and registering hooks – http://www.studiopress.com/resources and http://my.studiopress.com/snippets/
You could copy one of the widgets on the homepage and rename it since you only want it to show on the homepage. You’ll also need to do the same for the functions.php file since you’ll need to register that newly created widget at the bottom.
When you create your widget for the homepage, you’ll need to wrap it with your class or ID and you can control the css by adding it to your style.css file of the theme.
If this all seems to difficult, I’d recommend hiring a dev to handle it all for you.