If your job allows this to happen continually, then they could be held liable for creating a hostile work environment. It's not just coworkers who can get a company in trouble for sexual harrassment -- it's also if a company does not protect its employees from creeps like this guy.

You must bring this up with your manager. You must document every single time this creep comes in, and your other coworkers need to help with the documentation. Your friend, and also the other coworker should go to the manager about this. This is not for you to deal with, teenage girl in your first job. This is for management, corporate, or HR. By allowing this creep to continue to come to your store, your company is opening themselves up to legal liability.

Since the creep comes in at the same time, it's likely he has a "route" and he might hit several other stores, especially if he truly lives 45 minutes away -- he's going to go to all the stores he can. It is extremely likely he's been banned from the store next to where he lives.

But that information from your coworker is hearsay until your coworker can document it. How does the coworker know where the creep lives, and how does the coworker know he's a registered offender?

If he's not a registered offender, what he's doing to you is just barely on this side of the line of him getting on the registry. This is predatory sexual harrassment.

If he's making you uncomfortable, then you are already in a hostile work environment. This is absolutely not a grey area. This is black and white sexual harrassment -- and to a teenage girl, no less. FYI if it makes you uncomfortable, then there's about a 100% chance that it's not you. There is already an established pattern of this. You are not the only one who notices this. There is a history of this independent of your observations (your coworker).

This cannot go on. There's nothing wrong with being shy or reticent. None of this is your problem. You don't have to put up with any of this, ever, for any reason, for one second. This is a serious thing, and it is an issue for management to deal with. He's already done enough to be banned from your store.

Since this creep does the same thing every day, the police should be either called the next time or even waiting on him the next time. That way they can ID him, and if he's on the sexual offender registry, and is doing this to you, his ass is in jail.