Corn snakes spend the vast majority of their time hiding - especially baby corn snakes.
Quick thoughts:
1) Do not disturb/handle the snake until it is on a regular feeding schedule (has eaten 5 or 6 times).
2) House baby snakes in small containers - like the size of a shoebox or smaller.
3) Do not subject snake to bright lights.
4) Make sure the snake has hide areas.
5) Feed the baby corn in the evening - do not watch it eat. Put the food into the cage and leave it alone until the following morning.
6) Make sure your reptile is being maintained at the proper temperatures - with a temperature gradient.
7) Ask the breeder/store what the snake was eating. Some corns take frozen/thawed, while others like live food.
8) Your snake could be going through a shed cycle, if this is the case, it will be less likely to eat.