Tractor Supply is a national retailer that offers a wide variety of products for home, farm, and ranch. They sell everything from clothes and footwear to tools and hardware.
They also have a small selection of key blanks and key machines. However, they do not make keys.
If you need a new key made, you will need to go to a locksmith or hardware store. Tractor Supply does sell key machines, but they are intended for use by businesses, not individuals. Key machines can be expensive, so it is usually cheaper to just have a locksmith make you a new key.