Where can I find raw coffee beans in Murfreesboro, TN?

I am 14 years old. I applied for a barista job at Starbucks. They said I would be great, since I look so tall and mature for my age, but they said I need to learn how to prepare coffee from scratch. So I need to know where can I find raw, green coffee beans in Murfreesboro, or at least near it. any suggestions.