At six months he is still very young and immature - is he your first lab? Whereas smaller dogs mature faster, labs stay very puppyish until they're over 2 years old, and in the meantime they are very bouncy and excitable and clumsy. At his age they're also very mouthy and chewy, and they explore everything with their teeth. You've got him at a particularly bad time as he'll probably be smack bang in the middle of teething as well. Have a look at his gums and see if they're red or swollen (they may even be bleeding).
Regardless of whether he's teething or not, he needs plenty of chewy bones and toys to focus his attention on, instead of your clothes and shoes. If he is teething you should try to match the chew to the texture he likes - e.g. if he's going after hard plastic, get him a Nylabone. If he's going after fabrics, wet a rope toy and freeze it. Most dogs will alternate between chewing hard and soft surfaces throughout the teething process (softer to massage and sooth sore gums, harder to help the teeth break through), and unfortunately it seems like sometimes the perfect chew toy is our hand - soft on the outside, hard on the inside! Leather shoes are also a favourite, just the right amount of 'give' in them - not so good when it's your favourite pair! He's not doing it to be bad though, sometimes the pain of teething can literally drive them crazy.
The nipping and growling is just his way of trying to get you to play when he's excited - if you shout or point or run away, he'll think it's part of the game. Avoid any tug or chase games as these will encourage him to grab and nip, and focus on games like fetch or find. If he does get over excited and start nipping or jumping up, turn your back on him and walk away - he needs to know that biting = no play, and stopping the game will work much better than any amount of shouting - and also has the bonus of taking you or DS away from his teeth or claws while he's excited. Only ignore him until he's calm (probably just a few seconds) and then move his attention straight on to something positive, like a short burst of training with a clicker and treats. Above all, labs love to please, and they love food!
Rest assured though, as he settles in and matures a bit, he will grow out of it