Group obedience classes; all members of the family attend each class, and do all the home work and practice sessions individually with the dog. The fee is per dog, so no extra for the rest of the family to attend. This way you all learn the same things, and are interacting with the dog the same way, and giving the same hand signals.

Next, on walks, take a baggie with cut up bits of hot dog, cheese, boiled boneless skinless chicken breast. You want high value treats for this. Each time you see someone approaching, step to the side, have the dog sit facing you, you have your back to the other person / dog (so your dog can see what is coming, it is not behind and more scary) and you feed the treats. Basically you keep the dog busy with eating the treats, dog is focused on you, your hand the treat bag, and ignoring all else. It would help if the person / dog is across the road when you do this the first upteen times.

The treats: one hot dog can be cut into 88 pieces (I've never made more than 62) but you get the idea, these are SMALL size bits, and you just about shovel them in the dog's mouth when you first start this exercise.

You can desensitize to the bell sound, that will take about 2 to 3 weeks if you work at it for 1 minute 3 times daily. Ring a bell and treat. Have the dog sit, ring bell and treat. Back up 6 steps, call dog to come to you, ring bell and treat.

The trainer in the class will have lots of info for you, as well.