Does it matter what people think about your dog's behavior?
You should care, because when out in public your dog is an ambassador for canine-kind. If he behaves badly by lunging at strangers, jumping up, or barking, this is unpleasant and intimidating for others. However, a well-behaved dog that walks nicely to heel and sits politely to greet people is a positive pleasure.
A dog that behaves in public means you can relax and enjoy walks, rather than be on edge all the time in anticipation of problems. Remember, the dog and his behavior are your responsibility, both in moral terms and in the eyes of the law. Should your dog jump up at a senior citizen, knocking them over so that they fracture a hip, then you could well be liable for their surgical expenses.
To behave well in public means having the dog under control at all times, both on and off the leash. This skill doesn't happen by magic but by putting in the time with regular obedience training. Even a basic command such as "Sit", along with walking to heel, equip the dog with a great grounding so that he is able to meet and greet strangers without showing you up.
Training both puppies and adult dogs does require time, persistence, and patience. For the puppies, the world is a big exciting place full of new sights, sounds, and smells, so distraction is rife. For the adult dog, they may have deeply ingrained bad habits that need to be replaced with new good behavior.
For both young and old, be sure to use reward-based training methods. This rewards the dog's good behavior, which sets them on the path to thinking about what they need to do to please you and earn a reward. Old-fashioned methods based on dominating the dog are outdated because they use intimidation and punishment to cow the dog into obeying. Not a happy scenario!
Basic obedience training requires little other than:
A collar and leash to restrain the dog
Bite-sized tasty treats to use as a reward
A bag that clips onto your belt, in which to keep the treats handy
Time, patience, and consistency
Train your dog a couple of times a day for 10 to 15 minutes. You can also incorporate training into your walks, such as getting the dog to sit curbside. However, be sure to make training fun and always end on a high with a command the dog knows and can do well. This helps build self-confidence and enthusiasm for the next session.