If you have a small puppy, the first acquaintance is better to hold a cat/kitten in a cage. Do not use a carrying pouch or a bag, it should be a spacious cage for a cat. Lock the cat in the cage and enter the puppy (leash).
But, as in the case of an adult dog, the puppy needs to undergo initial training. Let them see each other, but don’t let the puppy get too close. Firm and calm voice command the puppy to “Sit” or “Down” around the cell. Give them 5 minutes, then take the puppy and treat him to delicious.
Go back and release the cat from the cage. Continue to introduce animals for 2 weeks. Let the puppy lies closer and closer to the cage. If the cat hisses and outraged – never mind. This is normal behavior in this case. The main thing is the control over the puppy.