Socialization is an important part of a puppy’s development, particularly between the ages of 8 and 12 weeks. During this time your puppy will not be fully vaccinated yet. Carrying your puppy in your arms or in a bag/carrier during this time for socialization is a great idea. You may be able to take them for short walks on pavement after their second vaccination. Please be guided by your vets advice
There are many misconceptions that socialization is introducing your puppy to as many dogs and people as possible. This is not entirely true. To properly socialize your puppy, you must introduce them to a variety of surfaces, situations, places, people, sounds, dogs and other animals in a positive manor. When introducing a puppy to anything new, do not force them into the situation if they are scared, be patient and reward them for interacting. You want each interaction to be a positive experience.
Here is a great checklist that you can work through with your puppy from Dr Sophia Ying https://drive.google.com/file/d/1GZFIwqkKg7tDW-ok3gv8V2yViEmhRNl1/view?usp=sharing
Remember to bring treats when out and about with your pup. Always reward positive interactions