Both your water heater and your fridge will run using gas Lisa.
I'm not sure exactly where it will be in your Swift (it might be above the tv worktop opposite the sink) but there's usually a thermostat for the water heater on the wall, often near to the one used for the blow air heating if fitted. After ensuring that all gas connectors and valves are on, turn the outer ring of the stat and a green light should come on then set the desired water temperature.