Once your dog can stay, you can gradually increase the distance. This is also true for the “sit.” The more solidly he learns it, the longer he can remain sitting. The key is to not expect too much, too soon. Training goals are achieved in increments, so you may need to slow down and focus on one thing at a time. To make sure the training “sticks,” sessions should be short and successful.
Any area that the pup has access to must be kept clear and clean. Put out of puppy's reach anything you don't want him to chew or destroy. Do not allow your puppy to have unsupervised access to 'unchewables.' Do not chase the puppy in an attempt to take something away. Instead provide puppy with her own toys and teach her how to play with them exclusively.