The process is the exactly same for older dogs as it is for puppies; prevent accidents from happening by using baby gates and a crate if possible, create a predictable schedule, learn to recognize your dog’s potty signals, accompany your dog outside and immediately reward for all outdoor elimination, properly clean any accidents and supervise your dog until you’re sure that he understands the rules.
Often, the sit command will be one of the easiest for your dog to learn first. Next, you can train your dog to lie down. At the same time, work on teaching your dog to stay. In addition, your dog should be trained to come when called as soon as possible. This is one of the most important fundamental commands. Once your dog has mastered these dog obedience basics, you can move on to fun tricks and advanced commands.
Remember that training is an ongoing process. You will never be completely finished. It is important to keep working on obedience training throughout the life of your dog. People who learn a language at a young age but stop speaking that language may forget much of it as they grow older. The same goes for your dog: use it or lose it. Running through even the most basic tricks and commands will help them stay fresh in your dog's mind. Plus, it's a great way to spend time with your dog.
When you have to leave the puppy alone, you’ll need to confine it to a crate. This will prevent the puppy from peeing and pooping all over your home, and will also help teach it control, since it won’t want to soil the crate. However, young puppies need frequent bathroom breaks, so you’ll also need to ask a friend or pet-sitter to stop by and let the puppy out throughout the day until it’s old enough to go for longer stretches without needing to use the bathroom.