no such thing as a stupid question - you either know, or don't - we've all been there
I thought you had to have your foot on the brake for the engine to start, but that may be left over from my previous auto. Nice habit though, brake on, clutch in, press start.
I put the key in my trouser pocket and leave it there. To unlock the car, press the little button on the door next to the handle (i love doing this - people think the car has fingerprint technology!) (You can lock it in the same way) There is also a little button for doing the same, next to the bigger boot release button.