It could take a few weeks for them to adjust. Going on walks or playing outside is a good way to let them burn off energy together outside of 'home territory'. Always support any good signs they are happy or relaxed near eachother and set boundaries to minimize potential stressors - feed them apart - have their own toys/beds - if the puppy is being a bother give them a bit of time from eachother instead of punishing behaviors.
If things continue