Typically, Labradors are pretty easy going and puppies are just curious and friendly.  So, unless you are unsure of how your resident (older) dog will behave/respond to a puppy then I think meeting one another is a special part of the welcome home time.  It can be good to have your puppy in his/her crate so that the dogs can smell and see one another without too much contact.  

Give your resident pet access to the crate area. Let pets smell and touch each other through the crate or pet gate. Do this several times over the next few days if you feel this is necessary. After that, give the resident pet access to the den area with your new puppy out of his crate. Supervise their meeting and go back to through-the-gate/crate meetings if trouble arises.  

Our recommendation of what NOT to do is to NOT introduce the resident pet with the puppy on the residents pet’s bed or near the resident pup’s food.  This could potentially make the resident animal feel protective of items and space and feel threatened by the puppies presence.  As long as you make sure to LOVE up and spend alone time with your resident animal(s) without the puppy then the animals typically are buddies within a few days and the resident pet won’t be jealous because of how you are still hugely loving on your first pet (s).