The more different experiences, people and places your puppy sees, the better! Puppy socialisation means getting your puppy used to the great wide world, and teaching them their place in it so that they know how to behave and won’t get frightened or even worse, aggressive, in certain situations.
Take your puppy on short frequent rides in the car, busy/noisy places, school playgrounds, shopping. Join your vet puppy parties, puppy classes etc.
When out walking, rest regularly, do not do too much at any one time, young puppies tire quickly and need a lot of sleep.
Introduce your puppy to hats, umbrellas, bags, boxes, the vacuum cleaner, ironing boards (opening and closing) etc.
Encourage your puppy to explore and investigate his environment, let him do this at his own pace.
Remember not to react in a negative way when you hear a loud bang etc., they will pick up on this.
Do not reward fearful behaviour by attempting to sooth, encourage or calm the puppy when it appears frightened, this often (unintentionally) rewards the behaviour. It’s normal for the puppy to show some signs of apprehension when confronting anything new and different.