I think it is a red maple tree. You can tell by the red petioles (stems connecting leaves to branches) and the leaf shape. I further clue would be the reddish brown stem color. It is probably a cultivar of some sort, but it will be kinda hard to nail that down w/o observing the trees behavior for an entire season. I would recommend going back to Wal-Mart in the spring to see what cultivars of map.ee they carry. I can't imagine that they would have very many options, and they probably won't change too much from year-to-year.