There are 2 options when considering how to go about teaching an untrained dog a basic level of obedience. One way is to hire the expertise of a local dog trainer either for personal sessions with just you or your dog or in a group setting. Alternatively you can buy a book or other self-help course to teach you how to train your dog yourself and solve common issues such as how to stop a dog pulling on the leash.
Working with your dog one-to-one on improving their dog obedience levels can be very rewarding. Many experts agree that you are often the best person to train your dog or puppy.