I want to get a fhestnut tree( the chinnese kind() it will come two years old h9w long will i have to wait for the first yield. how big will the tree get in a pot

The tree will not survive in a pot outside in NY over the winter. The roots will freeze and thaw and freeze and thaw and eventually begin to rot on you.

There has been a blight that has done a lot of damage to any of the chestnut family. It has wiped out most of the chestnuts in NY and has been around for many years now. So this may not be the best choice of plant for you.
If my memory serves me right, if you are wanting to eat the fruit you would want the American Chestnut, as opposed to the Chinese or Horse chesnut. I may be wrong on that one though.

Out here in Cheeseland they have no idea what, "Chestnuts roasting on an open fire" really means, or smells like. mmmmmmmmmmmmmmmm childhood memories. Dang! I am getting 2 old 2 quick!