For baby corns feeding one appropriately sized mouse a week for adults every 10 - 14 days, I would give it 2-3 days to settle in and then try feeding. Be warned though corns are insanely greedy - didn't know this with mine until she refused to eat for 3 months due to having gotten hugely fat. Took 3 months of an exercise regimen consisting of daily swimming lessons in the bathtub to get her hungry enough to eat. Corn snake are nocturnal so check at night for activity, 20-25 celcius is fine for corns and reduce it to 15 celcius to trigger the breeding season when their old enough.
Edit: she was fat enough that after she slimmed down she was 1/4 thinner - was feeding her twice as often as I should have fed an adult.