New snake owner

[Syrus]

Ok, so I have always liked hognose snakes, and have told my boyfriend I would like to get one in the future. Well I guess when I said that he heard "go out and buy one as a surprise for me a week later"
Luckily I have done some research into their care and had all the supplies already(I own various frogs and geckos)
So I now own Ravi a little male western hognose. The guy at the store told my bf that he was 2 years old and a good feeder.
I have NEVER owned a snake before, and am a little afraid I am going to make some silly mistake that most snake owners would know. I right now have him in a 10 gal (looking to get a 15 for him, but cant immediately so he will probably be in it for the next month)
with the warm spot being kept warm with a heat mat at about 88-95 degrees and I haven't been measuring the coolside. I have made a hide out of the furnishings in his cage, though he seems to ignore them completely and just bury himself instead, along with a water dish and about 3-4 inches of coco fiber on the cool side and about a half a inch on the warm side(its more shallow so the heat mat works better). I called the petstore and they said they last fed him a fuzzy on wednesday the 8th so I decided to wait until the 17th to feed him again. I read that they appreciate less humidity so I haven't sprayed or monitored it.
He is almost 100% hiding in the substrate, he came out the second day for about an hour to explore and other than that he just chills in coco fiber. I dont have any light on his cage, but do keep a window that faces his cage open to allow appropriate sunlight to help with this day cycle.

How often do they come out of the substrate? Is it pretty normal that he spends most of the time hiding? Anything I should be doing that I am not?
Also, what is the normal price for them? I asked my bf and he said he either paid $80 or $90 for him, that seems pretty pricey and just curious what is normal.