A lab is going to chew, especially when they are left alone and get bored. The best thing that helped with me was to get on to them when chewing something that they shouldn't and replace it with something that's ok to chew on. Over time they will get the idea. I never left mine alone and unattended in the house as a young pup til i knew I could trust them. Mine pups have all stayed in a crate or pen when I was to busy to keep an eye on them. I would also say that basic obedience traing would probably help as well, because you got a lab because you want to enjoy their company and its a lot easier to do so when they aren't running wild lol. Good luck with your pup and hope all goes well