Got the dress, now need it cleaned and altered

Is the dress the right length on you? If you are having it altered and need to have it hemmed, its possible that most of the stains would be cut off once the dress is hemmed. I imagine self tanner and red crayon won't be easy to get out without professional cleaning.

Gotcha. Of three stains (dirt, self tanner, crayon) I imagine the dirt will be the easiest to get out. Standard dry cleaning should do that, but I would worry that the heat from dry cleaning could set the crayon. I would recommend bringing the dress to a reputable cleaner near you (go to someplace with good customer service reviews, don't just go to the cheapest place because they might not be honest with you and might tell you then can clean in but can't) and asking them for their opinion and an estimate. A reputable cleaner should be able to look at the stains and give you an idea of what it might take to remove them and how much that might cost.