You must be committed to training your puppy in the early stages of his life when he is quick to take on new information and has not yet learned bad habits that will be hard to change. You will get the most out of training if you reward your puppy for his good behavior. Be careful not to punish his unwanted behavior, this will only make him unmotivated to perform the desired behavior at all. Instead, simply ignore the unwanted behavior and have patience teaching him new skills.
Teaching your puppy to sit should ideally take around 2 -3 weeks depending on how often you practice and how fast he learns new behaviors. The aim is to get him to respond eventually just to your vocal command for ‘sit’. You should vary the environments that you train in so that he does not associate one behavior with a particular place.