congrats, they're addicting, so be careful with that....
as far as hides go, i admittedly don't have hides in all my carpet cages and some that do have hides never use them... they just like to curl up wherever they may. for a hatchling though i'd say a couple hides would be best, one warm, one cool... the adults actually move their hides around from warm to cool if they don't want to come out. most of them really only use their hides extensively if they are opaque. if it's a neonate then some aspen or other loose bedding will suffice because they'll most likely just burrow under that or perch somewhere in the enclosure.
if it's a quality breeder you're getting it from, you shouldn't have to worry about a healthy specimen - they should all have had a few meals on their own and obviously have no defects or whatever. with jungles, it can be a toss up as far as determining which ones will turn out the best looking as adults, but if you choose a highly contrasted specimen then you probably won't be disappointed.
as a first herp, you may have your hands full, but if you provide warmth, water, food, and shelter you should do just fine... purchasing a neonate will definitely be a very rewarding experience, so good choice there! when you get it, it will most likely be very 'mean' but most do calm down, regardless of how much they're handled. ironically, my only jungle carpet is all piss and vinegar and is probably my meanest snake... not to discourage you.
the only other 'advice' i can think of is that you may want to feed it rats ASAP because jungle carpets in particular can be finicky and you really don't want your 6' long, 10 lb adult eating mice... that would suck.
well, sorry for the long post, but i guess i get excited when people get into morelia.