First things first. Let your snake get used to its cage for about 7-14 days without feeding, holding,handling(unless to change water or check temps). I don't think your snake is calm enough to eat right now(just opinion). Since he is new I would have a check-up done by a vet A.S.A.P... Check out this site as well it should offer some light to all your Boa questions: http://www.primareptilia.net/boa_care.htm. I hope this helps.

Forrest