Is there a Sporting goods or store that carrys a Cornhole set?

Answer 1

You can buy them online.

(it's a game, people)

Answer 2

I've heard of plastic sets sold in stores, but people aren't usually very happy with them.

Wooden boards can be purchased all over online (i.e. - http://www.cornhole-game.org/), but if you happen to know anyone who is handy with the tools, most people are currently building their own.

Check out the "Building & Customization" section of the forums at http://cornholeplayers.net for several different styles of building boards. There are some really helpful people who can answer any questions that come up along the way, too!