Navigation Bar and Ads

Hi there, I’m new to this, so forgive me if this sounds stupid 🙂

I purchased a theme for my site which is a child theme of Genesis 2.0. I’ve had some difficulty customizing the pre-made theme.

I’ve tried a number of codes to center my navigation bar, but have had no luck.

I’m also trying to place a banner ad above the header image or above the footer, but ended up with the white screen of death.

Any tips or tricks would be greatly appreciated! Please let me know what other information is needed. Thanks!

URL is http://www.ChicIsTheNewBlack.com