It’s common to see fawns by themselves. A mother deer will leave a fawn during the day, both to look for food and so her scent doesn’t attract predators to the fawn, which is nearly scentless. People often mistake a fawn as abandoned when, in fact, it is being properly cared for by its mother.
If you care, leave it there. In almost all cases that is the best thing for the animal.
If you find a fawn, give the animal distance. The mother will not return if you are present, which may delay nursing for a hungry fawn. Most often the mother will return at night or when no predators are nearby. White-tailed deer view humans as predators.
Even if you think the animal is injured, you still should leave it be. It’s best to let nature take its course. Wild animals are not pets. They may carry diseases and are not suited for captivity.
If you feel compelled to intervene, call a licensed wildlife rehabilitator. Keeping a wild animal without the proper permits is illegal. Most people are not trained in animal nutrition and do not know how to raise a wild animal without it developing a dependence on humans. The result is an animal that cannot survive in the wild.
A list of licensed wildlife rehabilitators and their phone numbers is at dnr.IN.gov/fishwild/5492.htm.