The "It's Me or the Dog" lady is a little nutty. I love that she uses hidden cameras though! I wish I had that equipment!
Getting a harness is bad advice. A harness evenly distributes the pressure the dog feels making it more comfortable for the dog to pull. Plus that pressure is reinforcing, making the dog want to do it more!
Leash Training: The easiest way with a puppy is to load up your pockets with FABULOUS treats. (Like tiny bits of cheese or hot dogs!). Go for a walk. EVERY time your dog pulls, STOP, and WAIT until you dog stops pulling. Say "Yes" and give your dog a treat. And then start walking again. It is super-frustrating and SLOW. You will only take one step at a time at first, but your dog will learn that staying close to you is fun, and pulling makes the fun stop. "Any behavior that is rewarded will be repeated." Reward the good stuff and the bad stuff will slip away and disappear.
Do get the crate. It is the best solution for chewing and housetraining! Teach him to go in the kennel on his own. Throw treats in there and pretend to ignore him. When he goes in, say "Yes" and give more treats in the kennel. FEED ALL MEALS IN THE KENNEL. I don't use kennels often, but my dogs RUN to their kennels when I ask them to. When you close him in the kennel he will bark and fuss. IGNORE IT. DO NOT TAKE HIM OUT UNTIL HE IS QUIET. No matter what! Otherwise you train him to be noisy! Poke treats through the side of the kennel whenever he is quiet. Keep the kennel in a living area of the house so he doesn't feel isolated.
Housetraining. Set an alarm and take him outside every 2 hours, after eating, after drinking, after (and during play) and after sleeping. Give him treats when he pees and poops outside. If you take him out this often, he won't get a chance to have accidents inside. Keep him on a little leash all the time inside so you CAN "catch him in the act" and take him outside right away.
Nipping is not hard to fix either. The easiest thing to describe in writing is when he mouths you, to grab his lower jaw, tongue, and hang on until he decides it isn't fun and starts to struggle. Then let go. He will 1) sit down and look at you. If he does, give him a treat and walk away. or 2) he will start to mouth/nip again. Do it again, wait longer, make it more un-fun.
That covers the basics. I haven't met a new puppy owner that DOESN'T have questions or problems with these things. You're not crazy - it's just hard to train a puppy to fit into a human household. It gets better. :)
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