why did billy decide to go for the dogs himself

Grandpa actually informs Billy that he knows a man who happens to be riding out to the depot in Tahlequah; Billy can ride with him if he wants. Billy is overjoyed but cannot wait. He becomes so impatient that later that night, he decides to pack some food and get the dogs himself.

What are some qualities/personalities that billy has in Where the Red Fern Grows. Also,what's an important quote he has. What are his physical descriptions/traits