Testing site with fake credit card or sandbox
I am trying to create an online store that will only be selling downloadable content. I have no experince setting up a commerce system and I am wondering is there a way I can test the site? I want to put a sample item up and price it at $20 and then buy it to make sure I have everything set up but I dont want to REALLY buy it if that makes any sense.
Thank you for the help in advance.