Socialize him as much as possible, as soon as possible.
Get him used to many different people of many different ages, sizes, races, both loud and quiet.
Hang out in parks, parking lots and even ask large store managers Home Depot and Lowes if you can shop with him.
Stop by a lot of pet stores, they usually don't mind at all.
Let as many people as you can, pet him, talk to you, shake your hand, hug you, etc,...he'll soon be able to quickly differentiate between friendly and unfriendly strangers and act accordingly.
Work with him diligently on obedience. Take a class with him if you don't know how to train him. Obedience school is where you take him to learn how to train him. They don't train him, you do.
Learn the basics of walking a dog. This sounds so basic, but many people have no idea of how to control a dog.
I hate to see owners being pulled by their dog. They're Not walking the dog, the dog is walking them, it's embarrassing. Many dogs become the Alpha without proper training. It's Not cute when your puppy growls or nips at you at any time. He's testing you to see who's the Alpha.
Properly trained dogs walk on your left side, their head even with your body. The don't pull on the leash and are Always aware of where you are, where you're going, anticipating your every step and will quickly turn left or right as you turn, running to keep up at your side if you sprint. They'll quickly slow down as you slow, again always remaining at your left side, even with your body.
Run in circles and they'll be right there with you at your side. Left hand circles have to be bigger so you don't run them over, but right hand circles can be hairpins, and they'll stay with you.
Whenever you stop, they should stop also, immediately sit, again and always, even with your body. Start walking they get up quickly and follow, stop and they go back into sitting.
You should Never have any pressure on the leash while walking, they should anticipate EVERY move and be right there with you.
Dogs are incredibly smart, loyal and easy to train, you just have to be consistent.