Don't worry, it's very normal for corns to hide a lot. Firstly, it's their first week so they may be still getting accustomed to it's new home, after a while it will probably start coming out more and searching for ways to escape!
secondly, each corn is different, some are out all the time, and some do stay hidden a lot, and thirdly Corns are naturally nocturnal, so the best chances of seeing it are in the evening and late night hours, I swear I hear mine burrowing when I sometimes get up in the middle of the night!