I am working on a project where I’d like to use stock photos. I am however confused about what is and is not allowed. What types of usage are allowed and when/how to refer to author.

My project has no real name that I know of. I want to create some cards that have tips on them. For example say my topic was food (it is not) I’d have one card for carrots and on the back would be nutritional/medicinal uses and a tasty recipe, another for apples etc. Then I’d get a stock photo of carrots for the front of the card to make it more appealing. The photos will contribute to sale because it makes them beautiful.