It can be all. If the APU is u/s, it will be necessary to use a ground air start truck and a stationary start is required, then disconnect it when one is started. You can then push back and when brakes are applied, start other engines using a crossbleed start technique. Normal operation is to start during pushback, partly so that the tug does not have the all engines running idle thrust to push against.
Landing lamps for aeroplanes are very expensive. One does not want them on all the time, they can cause unpleasant flashing effects in cloud. Normal procedure is to only illuminate them continuously below 10,000' to enhance collision avoidance. Turning them on at other times to say 'hello' or 'I'm flying over now Mum!' is not unknown, though discouraged.