Your freezer needs some time to settle before you can start using it. Let it stand unplugged, in an upright position, for at least 4 hours to allow the compressor oil to settle.
You can plug your appliance in once 4 hours have passed. Make sure that the thermostat control is set to ON but don’t start loading food right away. Allow your freezer some time to cool down to temperatures safe for food storage, which might take up to 12 hours.
The ideal freezer temperature is -18 °C. Check the temperature inside the freezer with an accurate thermometer. Place the thermometer inside a cup of alcohol or cooking oil and put it inside your freezer. You can begin storing food when the desired temperature is reached.