As mentioned above, puppies respond well to positive-reinforcement based training. It is important to acknowledge that dogs cannot possibly know which behaviours are right and which are wrong - it will be up to you to teach them. Take the time to show your puppy what you want them to do and reward them with a treat, praise, or a game each time they do the right thing.
To be a successful pet shop owner, manager or employee, you need to be able to sell merchandise, from pet food and toys to cages, fish tanks, leashes and the pets themselves. Obviously you need to know about caring for different animals in order to keep the animals you are selling in good condition; and advise customers on the products they might buy. Some pet shops may be more caring for the animals than others.
Ideally, dogs should be taken to council-designated areas where they can be safely let off the leash to run free. It is important to use these specifically designated areas not only to ensure their own safety (preventing the risk of being hit by a car) but also the safety of farm livestock and wildlife which can be threatened by a dog let loose in their habitat.