Dogs are social animals and most enjoy the company of others. Just like humans, some dogs have more outgoing personalities, and others are more reserved. Proper introductions are important to ensure the relationship gets off on the right foot.
Before bringing home your puppy prepare your house. A crate, gate, or exercise pen are all great tools to enable you to separate the dogs quickly, and to contain your puppy when they are not being directly supervised. A helpful tip would be to establish a routine from the very beginning as well.
When it's time for the dogs to meet a neutral place can help both dogs to feel more relaxed. An unknown puppy barging into an established dog's home can seem like an intrusion to even the most laid back and mellow dog. You might take your older dog with you when you pick up your new puppy, for example, allowing each dog to ride in their own crates so they can begin to become familiar with the smell and sound of the puppy before having direct contact. Another great solution is to take both dogs for a walk in the yard on short, loose leashes before entering the home together.
Initially you will want to remove all high value items such as treats, toys, chews, and beds from the areas the dogs have access to. This will prevent your dog from squabbling over these items with the newcomer. Once the dogs have begun to get along you can slowly reintroduce those items making sure each dog has their own.
Supervise all interactions between your puppy and older dog at first, growling from your older dog is a normal aspect of dog communication, it is how one dog tells another dog they have crossed the line, and it helps to establish boundaries. It can be acceptable as long as the older dog doesn't make inappropriate contact and injure the puppy. You can however redirect your puppy to another toy or task, especially if your older dog starts becoming agitated.
Giving your dogs periods of separation throughout the day is helpful for both dogs. It will keep your older dog from feeling overwhelmed by the energy of a puppy. And your puppy may still need 16 hours or more of sleep per day and may be reluctant to nap appropriately if there is too much excitement happening. No one wants an overtired, naughty puppy wreaking havoc on the house after all. This separation can be accomplished by crating either dog or placing your puppy behind a gate or x-pen. Puppies are still developing their communication skills and will have a lot to learn from both you and your dog.
"Puppies immediately start looking for someone to play with and when they can’t find another puppy, the adult dog is the next best thing. Your dog may or may not appreciate this! You must carefully supervise any interactions to keep both dogs safe and happy." -AKC
Some other tips include rewarding both dogs for behaving appropriately. Make sure your puppy has enough mental and physical stimulation throughout the day so they have outlets for their energy. Walking both dogs at the same time is a great way to allow two dogs to socialize as they aren't focusing all their energy solely on each other.
And don't rush! A relationship is formed over time and that is okay. Eventually your puppy will develop the communication skills they need to become successful, and your dogs will become great friends.