What you have there is a Dekayi Brown snake. They are a very small non agressive snake that eats worms and garden slugs.
They make fine captive pets and do not require any special set ups.
A small tank or animal enclosure, a place to hide and a water bowl is all you need.
You won't be able to feed it in that enclosure, slugs and worms are sticky, the fibers will stick to the food.
These snakes prefer cooler teperatures, so do not use any heat lamps or tank heaters.
They usually hunt for food at night, early in the morning or right after a rain storm.
For feeding you may purchase a package of night crawlers at wal mart back in sporting goods, it is sold as fish bait.
The worms will be too big, so get used to cutting night crawlers up with scissors.
This one eats worms from human hands...
A small cup full of good food, small worms and garden slugs.