Kids often need to be taught how to make eye contact, smile and respond to polite chit-chat. Teach your child basic social skills by making games out of these things and practice it at home.
Teach your kid how to communicate with others. Start simple, like teaching your child about greetings – "Hi, how are you?", "My name is…", "Do you want to play?", "Can I play too?", "Hi, I like your…" – simple things like that will help him/her mingle around easily.