I'd recommend letting them meet on neutral ground. That is, not at your house but maybe at a park. Since your current dog is still young, it may be easier to teach him to get along with your new dog. And make sure you keep up with your current routine. If he sleeps in a certain area, don't change it. Keep things the same for him. Also, make sure both get seperate alone time with you and bonding time together. Good luck.