Rough Greens are not an appropriate first snake. They don't like to be handled. They don't eat predictably in captivity. They need a varied diet which can be hard to find. (I kept one in captivity for over 10 years, so I know what I am talking about. I only took on that responsibility because I had 15 years of extensive snake keeping experience prior to finding mine. And still, it was a pain.)
They only reason they are sold as a good beginner snakes is because they are easy to collect in large numbers if you know how and they are cheap. Most of the ones you see in pet stores are destined to a slow, unpleasant death.
Get a captive born corn snake, you will be much better off.