To train an older dog you just need to apply common sense approaches like being patient.
Dogs take time to adjust because they have their own histories, which is what makes them nervous about new surroundings.
Adjusting may take anywhere from a few days to a month or so. Once they realize they have arrived in their new forever homes, they should soon settle into being part of the family.
Consider crate training
If they aren’t house trained to your satisfaction you should treat the adult dog just as you would a new puppy. When you train an older dog, this may mean keeping them in a crate when you are not able to supervise.
If you take this route, when you release them from the crate, take them immediately to the place outside where you want them to relieve themselves. If they do not relieve themselves, re-crate them and try again a little later. If they are new to crates, introduce the concept slowly.
Because adult dogs are perfectly capable of learning new things, when you train an older dog they could well benefit from learning the basic commands, such as lying down or being walked on a loose lead. An obedience class may be a great place to work on this training.
They can also socialise with other dogs and people. It will enable you to watch how they react to other dogs and even strangers in a safe environment with a professional trainer nearby to offer advice.
When you train an older dog, start teaching them the rules for your home as soon as possible.
Consider teaching self-control using something like the “Nothing In Life Is Free” (NILF) method. This requires your dog to behave in an appropriate fashion prior to being given the treat, walk, or positive attention they desire.
Nothing In Life Is Free
Be sure everyone is on the same page. Dogs get confused when different members of the household have different standards of behaviour, commands, or expectations.
Because you probably aren’t aware of the sort of experience your new dog has had with training, positive reinforcement methods are the best bet. Using a few quality treats and lots of praise are tried-and-tested training methods for dogs of all breeds and ages. Just remember to keep things fun and upbeat.