ive just brought my first puppy too. it takes patience and time and also persitance. practise every day with them and they will learn.
i dont believe in hitting my puppy either just being stern and showing him im not happy by locking him in a room alone or leaving him alone and walking away and not looking at him.
before you brought him you should of did a bit of research into if he will be good with kids but i feel if the puppy grows up around kids then he will get used to them and will be good around them.
im curently teaching my puppy not to jump up when we get home or anytime at all unless we ask him to as i have neices and nephews and my puppy will be a big dog and i dont want him knocking them over.
puppies always chew everything they can and bite to investigate new things. always put things out of reach that you dont want the puppy chewing or you can use bitter biter spray that you can spray on anything you dont want to be chewed by him. if he tries to chew it it will taste yuck and he wont want to chew it anymore.
good luck with your new puppy and if you are having trouble just pm me if you like and i can help. where are you located???