Dog Obedience Training For Your Pet Dog

I have a 6 month old lab/shepherd mix. She is full of energy. How should I start off training her? With a walk first, so she’s a bit calm for the obedience training?

I have 2 pitbulls a male and a female, both fixed. Female is almost 3 years and male is about 2 and half.

I also have 2 kids, a 19 month old and a 3 month old. Female dog, absolutely fine, loves them. male dog fine with baby, getting worse with toddler.

Sometimes the male dog is fine, licks and plays with my son (oldest) but since he has started walking (about 3-4 months ago) he has started growling at him. Which worries me immensley. I love my dogs and treat them like my children. However if i HAD to i would give my dog away and if it came to it i may have to get him put down. I really do not want to get rid of my dog, i love him so much. But im not willing to risk my childrens lives.

I live in new zealand and they have a zero pitbull/big dog policy pretty much, pitbulls HAVE to be neutered (so they will eventually die out), muzzled in public and on a lead at all time. If a pitbull is given to the local spca (the only shelther there is) they are put down immediatly. They do not get judged on a case by case basis. However my dog wouldnt pass the temprament (sp?) test anyway. he is terrible with other animals and now kids .

When he was a puppy he had LOTS of socilization and obediance training until he was about 8 months old. We are thinking of starting it up again, but would it help or should i start looking for a new home for him?
he gets daily exercise with my husband he takes both of them on an hour-hour an a half walk every day
so its best to get him put down? i feel so guilty getting him and then doing that to him. its not fair. guess im going to have to have a serious talk with my husband. guess all my family (parents, grandparenst etc) will be happy

is it possible to teach a dog to sit, down, and stay in two hours. Theres a reputable k9 trainer that used to train K9s for Airforce in my area. He claims he can train any dog in 2 hours, if this is possible Im gonna get him.

I mean the schools that are like Bergin. Can you be a service dog trainer (for other people not just your dog) if you know what to teach them? Is it if you go through that certain school do they give you a certificate of some sort that tells you that you are allowed to train them a give them to other people?