Overspeeding And Stalling Options

[AspiringPilot]

Everytime I take off and Im in a 747 and then Im going to the altitude ATC tells me to go I always tend to overspeed. So here's the question..How far back should you pull the throttles prior to take off? I also was wondering how long into a long haul flight can you have flaps down to reach cruise? OKay I have another question....How much pounds of fuel approximately does a 747 need to do a long haul flight from KJFK-VHHH? Which is also known as HKG.