If I have created a product, do I see if a company is interested in it first or do I need a copyright/patent for my idea/product before I do?
In order to protect your interest in the product that you created you should consult with a patent lawyer about patenting the product in the United States Patent and Trademarks Office before showing it to any company representative for sale.
If you let the company see the product without any agreements or a copyright/patent then you run the risk of them using, tweaking, and profiting from your idea without any compensation for yourself. The best route is to get the patent. Patent law is very specific-- so you will need a patent attorney if you want to make sure it's done right so that your idea is protected. There are some kits out there-- but if not done properly, you loose some of your protection.
A secondary alternative is to have an attorney draft an agreement regarding your disclosure and their access to your product. This isn't quite as good as a patent, but it still gives you some enforceable rights later on if you have a well worded disclosure agreement.