Indiana is one of the states that has a restraint statute, which means that dogs must be restrained at all times. Otherwise, if the dog bites a person when not restrained the owner is subject to civil liability and criminal penalties. (Cite needed; definition of "restraint" needed; discussion of local Indiana ordinances forbidding dog tethering needed.)
Scheduling multiple training sessions throughout the day will help your dog learn more quickly because dogs like schedules and he will depend on, and look forward with happy anticipation until you can go out again! I like training right before breakfast, lunch and dinner because my pups are hungry and pay more attention to me, and I can even use their kibble (food) for reward!
Make the puppy come to you. While he’s on his way to you, still wearing the leash and collar, back up a few paces and then reward him when he gets to you. Continue the progression until your puppy, upon hearing the cue noise, comes to you and walks with you a few paces. Remember that puppies have a short attention span, so keep your sessions short, and end them when your puppy is still eager to do more, not when he’s mentally exhausted.