It happens every now and then - people find baby wildlife, all alone. With a raccoon, this can happen for a variety of reasons. The mother raccoon may have perished, and the very rugged and determined young may set out on their own. Or perhaps a mother raccoon moved from a den to a new den, and had to make a judgement call to leave one behind - that happens. Or, very likely, the raccoon isn't an orphan at all. Mom is just sleeping somewhere, or off gathering food, and the youngling wandered off. Mom will still find it. Here is what you should do in your situation.
infographic by: www.raccooncontrol.ca