What I usually do is Google.
For example. I wanted a discount on an Amtrak train ticket.
I just put into Google "Amtrak coupon code" and I got a bunch of hits. And yes I did get a discount.
Some codes have restrictions or have expired you'll have to look very closely. There are many many sites that offer coupon codes, so look around before you commit.
Try Googling the name of wherever you want to buy from and the words coupon codes.
I hope this info helps.
