I have been shooting for many years and even i still ask as many questions of the sales man about the firearm im buying. From how to take it apart to clean it to what ammo's best for this weapon. I would say there is not such thing there as a stupid question but we know thats a lie.
But there is no such thing as a stupid question when it comes to knowing your weapon and being safe.
Try to learn as much as you can from the sales man if he says he's not sure then ask someone else because most likely the sales man is not going to know every thing about every gun. WDB is right on with take your time to learn. knowledge is power. and in this case might save your life or great bodily harm.