You need to keep a watchful eye on your pup at all times. His environment, food, and social factors can affect him in different ways. Most importantly, he can become deathly ill with some of the illnesses that befall puppies. When you need to identify a problem, be sure to include your vet in the process. He will know the appropriate action to take.
Symptoms to watch for in your new pup are diarrhea, vomiting, coughing, sneezing, lethargy, pain of any kind, no appetite, and a fever. Dogs cannot tell us what they are feeling so we have to watch for these symptoms and call the vet to see if they need to be seen. Make sure their vaccinations are all up to date. Also monitor his contact with other dogs as they may be sick and the owners may not know it.
Once you see the vet and decide on a course of action, he may decide some medicine would help the animal feel better. There are several ways to get the puppy to take the medicine whether it is liquid or tablet. Some dogs may spit it out. You have to keep trying until they get it down or call the vet and see if something else can be done.
For liquid medicines, some dogs will lick it right off a spoon or out of the dropper. You can pour it in some food and mix it up. If the dog is uncooperative, you can hold him by the back of the head. Pull one side of the mouth up and shoot the medicine toward the back of the mouth and they will swallow it.
For tablets, the same thing applies. Most people will disguise the food in a piece of bread or in the dog's food. Some dogs will take it right out of your hand. If the dog is uncooperative, tilt your dog's head back and place the pill as far back on the tongue as you can get it. At no time should you hurt the animal while giving medicine to him.