Can I provide a "coupon code" for people to get discounts or free products?

No, it is not possible at this time to create a coupon code for discounted purchases.

However, you can create a COPY of the product and rename it XYZ Product-10% Discount or XYZ Product-Spring Break Bonanza, etc.

Then depending on how you are marketing this discounted product, you can use the URL link or the Buy Now button code located on the last tab of the wizard for this product in your emails and on webpages specifically for marketing the special product.