Any puppy will be leery of new people if he hasn't been around a lot of different people. Socialize, socialize, socialize. Puppies that are not socialized can become fear biters or aggressive, regardless of the breed. Max, my IW was afraid of new people, when we first got him. At 5 months, he had never been off the owner's property, been around kids, men, etc. She gave all her own shots, etc. and never even took the puppies to a vet. He would growl and back up when anyone came to the house. We took him everywhere, pet fairs, bookstore, Petsmart, Petco, local parks, etc. to get him over it. Pyrs typically are protective and territorial, but not overtly aggressive. They usualy will go up to almost anyone for petting, loving, etc. They are very social dogs, providing they have been exposed to a lot of different people and circumstances. Don't worry about him not protecting you if the need arises, just because you have socialized him. It is instinctive to protect what he considers his, but you don't want him to be aggressive. It is 2 totally different things. Whenever people come to your house, let him out to sniff and meet them. This way he will understand that you have guests over and they are good people, too.
Kathy