That's a pretty little snake you got there. And to keep him happy all you "need" is:
-dry terrarium with a tight fitting lid, not airtight - just escape proof.
-substrate like paper towel or newspaper or astroturf or ...
Not cedar, not wet, not small loose material that can be swallowed if you're going to feed him on it.
-warmth at 85F max during the day and down to maybe 70F at night. This is approximate 'cause ... (what's it like outside where it was caught?).
-water dish for drinking and bathing and feeding - always kept clean and fresh.
-privacy (dark, safe place) such as a cardboard box. A shallow one so he feels secure.
-fed easily on small, whole fish (see posts above/below)!
At this time, science has suggested that these snakes do not require a UVB light source however if you can provide it correctly, this would be great as it is more "natural" and may help in the long run.
-information here is free and the people intelligent (way more than me) with lots of experience (good and bad).
Y'all come hear?,
Michael