Adding Top Navigation To A Theme

Hello. I bought a theme for wordpress and it did not come with a top navigation at all. I would like to know how to add one myself. Any help appreciated.

I have contacted the developer and he was not interested in helping me at all. He was all about getting me to purchase the theme and after doing so he “is too busy”. The theme is called Tasty, here is the link for reference. http://whalesalad.com/tasty/

Thanks!