Which gear would you use to move forward from a stop?

Answer 1

For a normal passenger car, it would be first gear. While you might be able to move from a dead stop in second gear, this puts a lot of strain on the drivetrain, and causes excessive wear.

In commercial vehicles (tractor trailers, dump trucks, etc), and dependent on what transmission you have, and what the vehicle weight is, you can often start off in second or third gear... you could often even start off in fourth or fifth, but again, the matter of excessive wear on drivetrain components comes into play.