Often you need to move off at the same time as you steer round an obstacle such as a parked car.
Remember P-O-M - Prepare Observe Move
See Moving Off
To move away at an angle you will need to move off very slowly to give yourself time to check all around your car while you are pulling out and to steer.
To do this you need to use clutch control.
Lift the clutch pedal to just past the biting point and press the accelerator until the car starts creeping forward.
Keep looking all around for other vehicles, pedestrians, motor cyclists etc. as you pull out.
Keep the car moving slowly to give yourself time to steer the car around the vehicle in front.
Again keep the car slow as you will have steered a lot to move out around the vehicle in front, you will need to steer a lot to straighten back up.
If you see any vehicles approaching whilst manoeuvring out you may have to wait for them to go past as you will be using more of the road.