When I jacked up the front of the car, I noticed the jack must be pulling the car forward several inches. I got a little confused because when you use the front jack point, the car tilts so the drivers side is a bit higher. Once I got the car high enough to put stand under the passenger's side, I put that stand in place. I then put the driver's side stand where it "should" have been once the car was lowered enough for it to settle on that jack stand. Once the car was low enough, I noticed the driver's jack stand wasn't in the correct position. Further, once I got everything in place, I went to look at the wheel chocks in the back. They were a few inches from the tire. I have to assume the car moved forward as it was being jacked up. Should this happen?

Please let me say that I know jacking up a car isn't rocket science, but it's really hard to find clear and consistent answers on the correct procedure. I have a few questions:
When do you engage the parking brake when jacking up the vehicle
When jacking up the back, should the car simply be in park
When jacking up the front, should the car simply be in park

Thanks for bearing with me on this!!