this is a generic product page for wood sold at your local home depot, the size of the wood that is in the bin is what they have for sale.
Bear in mind that this has poor structural strength because of the C grade core, and that the best side still isn't made for "pretty," it's plywood, and can be used where a sheet of wood is useful.
In most cases they will make 1 or 2 cuts at no charge. You really need to call your local HD to verify their specific policy since not all locations are the same.
A 4x8 sheet of 3/8 plywood is approximately 34 lbs.
I do not believe this can be done via online services.
Yes I used it for a floor
It is .375 inches thick.
Yes, nothing in my neighborhood.
no this a interior grade plywood so it is not treated
Yes. Find an assistant in the wood dept and ask them. They will gladly cut the sheet to any sizes you may need but there could be a small charge for this service.