I just joined Adobe Stock today and I accidentally purchased an additional license of the same image thinking that would de-watermark it. Can someone please explain what would I need an additional license for? Is there any way I can delete it and get my credit it back?
If, for example, you wanted to use the same image for different clients, you would need to purchase a license for each client. See section 2.4 of the Stock Licensing Terms - Adobe Stock Help | Common Questions
As you purchased a duplicate image by accident, I've added a license credit to your account so you can select another image.