When did your puppy start greeting/ playing with dogs politely?

My 3,5 month puppy always starts the encounter by being afraid, then being overexcited and jumpy, following the other dog to sniff, barky and you name it. The only good and calm short greetings were with old dogs. Is this normal puppy behaviour? And does this improves just with time? Is there I can do to help him? It's like he is either afraid and barks at them or he is too pushy and in their face...