The Boxer is happy, friendly, intelligent, attentive, and loyal. Boxers develop strong, close bonds with family. They have lots of energy and a serious demeanor, though they can be clownish and playful as well. They like to grab and carry around just about anything they can in their mouths. Boxers tend to get rowdy when the food bowl is empty. They make excellent guardians and companions.
Teach him to come when called. Come Jasper! Good boy! Teaching him to come is the command to be mastered first and foremost. And since he'll be coming to you, your alpha status will be reinforced. Get on his level and tell him to come using his name. When he does, make a big deal using positive reinforcement. Then try it when he's busy with something interesting. You'll really see the benefits of perfecting this command early as he gets older.
It typically takes 4-6 months for a puppy to be fully house trained, but some puppies may take up to a year. Size can be a predictor. For instance, smaller breeds have smaller bladders and higher metabolisms and require more frequent trips outside. Your puppy's previous living conditions are another predictor. You may find that you need to help your puppy break old habits in order to establish more desirable ones.