Driving unnecessarily close to parked cars more than once is likely to fail the driving test. Try if possible to leave at least around a 1 metre gap (or a car doors width) from the side of your car to the side of the parked car on the left. This is in case a car door opens and with this distance you should hopefully avoid it. It is of course not always possible to leave a 1 metre gap.
If the street is narrow with parked cars, try to keep an equal gap either side from your left and right side, whatever this distance may be.
You must judge gaps between parked cars and you and moving or parked cars on the other side of the road before you enter any gap. If in doubt hold back!
If you consider it safe to proceed, you must slow down to an appropriate speed which it likely to be around 10 - 15 mph or even Lower. You must use good judgement. Driving in a confined space during a driving test is acceptable providing the speed is suitable.