You don't need fresh corn, you can use canned Green Giant whole kernal corn. If it's fresh you want, go to any supermarket, they'll have both, or should.
Lombrae
It is kinda hard to tell you where to buy corn if you don't say where you are, what type of corn you want and how you are going to use it. Be a little more specific and I am sure you will get some good help.
Just go to your local grocery store. They should have lots of selection. Presidents choice, green giant, its all good. Try to get the regular sized kernels, not the little ones.
Where do I buy quadrotriticale? And don't say Sherman's planet, or have the U.S.S. Enterprise pick it up for me........lol. I'm pretty sure they don't deliver.......lol.
TSC will have the machinery you need to grow and harvest your corn........lol. It's an awesome store, but, I don't think they carry the seeds..........lol. Corn'R Us maybe.....lol.