you need to leave it to settle, unplugged for something like 6 hours or so. The instructions should tel you. After that just switch it on and stick your food in it. Not sure how quickly the freezer bit will be ready tho.
The instruction manual should let you know how long to leave the fridge. I have just bought a fridge/freezer and was told to leave it switched off for 4hrs (allows the coolant liquid too settle from transit) and then swtich it on. You then leave it empty until it reaches the required temp and then fill it.