Since homes and expectations can vary greatly. It is best for you to not worry about what your new pet may or may not know, and just start from scratch teaching him exactly what you want by breaking things down and praising positive behaviors and responses.

Start immediately with your house rules. Building a strong trusting relationship with boundaries, leadership and mutual respect will cement the friendship that you desire!
Leaders are calm, and assertive so enforce the house rules this way. Establish your leadership position. Have your dog work for your attention. For example; have him sit before petting him or have him sit to get his leash on. Enter and exit through doors first. Touch every part of your dog. Get him use to having you handle him. Touch his feet, ears, teeth, toes, tail. This will also be useful when you need to brush his teeth, or give ear medication or trim his nails. Consider hand feeding your dog a small amount from his bowl before giving him the whole bowl of food.
Safety is a big part of a dogs’ world, so we must make them feel as if we have things under control. When your dog sounds off an alert bark then you should investigate the bark and give a release word like “thank you”. Your dog will know the situation has been properly addressed and there is no danger. If we do not address the situation your dog will escalate and potentially become an excessive barker or worse.