Now my post following your post sounds silly! Oh well.
You really should not start socializing your puppy until 4 months of age so that all of the vaccines can be given (if you're in North America!) Come to think of it, I'm not entirely sure where you live. I'm in London, Ontario, Canada by the way.
In North America, dogs don't receive their rabies vaccine until 16 weeks and therefore should not be exposed to
any other animals, except the ones currently residing in the household. After that, it is a good idea to take the puppy with you whenever you can so that he becomes accustomed to car rides, and not ones just to the Vet, as well as sights and sounds.
I think I read somewhere that you had already lined up puppy training classes. If I am mistaken, please correct me. Those classes will be a great first step in introducing your dog to other dogs. Take it from there as I'm sure you'll learn a lot in those classes.
Since I don't own cats, or exotic birds, I can't offer any sound advice on that. From what I've heard from our other members, usually an adult cat will naturally put the puppy in its place and one may have to supervise the cat more than the dog. I honestly don't know what either of my two, that I have now, would do if they encountered a cat as I'm not sure they've ever been close to one. My previous 2 dogs (a Golden and a Lab) would have considered the Cat to be prey, plain and simple, but they didn't grow up around them.
I hope I've been more helpful this time.
