You're very lucky under these circumstances. I am,good you or your pup going again.
Gun shy should be called gun fear. It is all fear based. You are the trainer owner protector provider. Think what would make a dog so fearful it would interior it's routine. Of your start thinking about how a dog perceives things, not how a human perceives things you will be much farther ahead of the game than most. That will enable you to make good choices for the dog. You know now if multiple people arrive thenbtoubhave to go.
Letting a pup run amongst other dogs is as bad a mistake as the gang bang hunt. Make it super easy for the pup. Let that pup see it Hit the ground water.