On all the automatics I have driven you remain in D when stopped at traffic lights. N is only used for things like pushing the car around the workshop without the engine running. You go into P when parked as it also locks the transmission so the car cannot move.
But I have never driven this particular type of transmission. It could be different. Hopefully someone will correct me if I am wrong.
You soon get used to automatic transmission. The secret initially is to concentrate on keeping your left foot firmly planted on the floor so you wont be tempted to try and use it. (Never drive with one foot for brakes, one for throttle ) There may be one or two other things to learn such as putting your foot on the brake or pressing a button on the lever when changing a selection.
You may also find it strange at first that engine noise may not always match what you expect from road speed . Or that the amount of engine braking may differ from what you are used to in a manual car. Could be more or could be less. You soon get used to it
I found it more difficult when going back to a manual car . I keep forgetting to change gear