Honestly, dogs are dogs. They want and NEED to be treated like dogs. That means being allowed to use their legs, to meet other dogs (of the appropriate temperament and size, a Saint Bernard might squish a Chi without ever meaning to.) And of course the usual training (Sit, come, No, Quiet, Etc.) We have lots of dogs on our street. A few of them are toy breeds, Chihuahuas and Chihuahua mixes. The nicest, politest ones are the ones that get regular walks and training. The nastiest one got no training, few walks, and little socialization. The only difference I can see is that the smaller dogs have smaller bladders and can't wait as long, but that doesn't mean they can't wait at all, just not as long as bigger dogs.
Our current dog had lots of accidents as a puppy. We put it down at first to the number of weird things she kept swallowing before we could stop her (paper, bugs, grass, etc.) We finally had the vet do some tests, discovered a bug picked up from water. And got her fixed. The Point: despite all those early accidents where she didn't get outside in time, she is now perfectly house trained. Things get better. Start looking for things about your pup you enjoy. The puppy energy is a bit shocking when you've been used to an older, slower dog. Start enjoying the fact that you have a dog who WANTS to and can play.
Oh, puppies are cute. Can we pleeease have pictures?