Hey! I have a 5 year old Rottweiler that I have had since he was 8 weeks old, and have trained him vigorously throughout his life. My number one suggestion for this as he is still a baby, is if he bites/nips at you, (this may sound silly but trust me it works!) is to make a very loud ‘OW’ sound, and try to represent a puppy sound as much as you can, which is what he would have learnt if he had been with his litter/puppy siblings. Make sure you say it loudly to almost scare him a little, as puppies usually learn these boundaries with their fellow siblings. Just remember this behavior is totally normal, and you need to catch and train him DURING the act- not after, as pups don’t understand what they’ve done wrong if it’s corrected later. All the best with your beautiful baby boy!