In transit, your appliance gets shaken around, so it's best to let everything settle before you plug it in. If it was transported upright, give it at least an hour before you plug it in. If it was transported on its side, turn it the right way up and leave it for at least four hours.
On average, full-size refrigerators take 12 hours to cool to the FDA-recommended food-safe temperature of 40°F. However, cooling time varies drastically by refrigerator type and brand, ranging from 2 to 24 hours. Mini fridges are ready quicker with an average cooling time of 4 hours.