Along with this sentiment I share ^ I would like to toss you a welcome to the forums. We're all here to help eachother and the advice given has been very good.Walmart flushes all returns. Please, please, please start doing much more research on the fish you are planning to get, before you purchase them!
In my experience, it's best to research any critter before purchase along with proper methods of setting up their habitat. Tanks generally require a month to setup their water and beneficial bacteria before slowly acculmating fish to their new environment. This will lessen the amount of causualities you (and the fish) suffer.