Pugs are very intelligent, but they can be rather willful and therefore not easy to train. If they realize that their cuteness allows them to get away with not doing what you require of them, they will use it. Punishing and yelling does not work with the pug, it only makes things worse.
There are two things the pug loves more than anything else in the world: fellowship with their owner and food (some say that the latter goes first). Use it. You will go a long way if you reward your pug with praise, a hug, or a tiny bit of food every time he does something right.
When it comes to potty training, remember that pug puppies under 12 weeks of age cannot control their bowel or urinary movements, their muscles are not yet strong enough. When the puppy needs to “go,” it will, and they don’t understand that they are not supposed to do it in certain places.
There are several different methods of potty training, and no matter which one you use there will be accidents. The best way to deal with them is just to clean up and continue your training. Don’t punish the dog; it is learning. If you stick to what you are doing, you will achieve the desired result.
If there are persistent behavioral problems, like chewing, you will need to do some more in-depth pug study (there are plenty of good books on that), or turn to professional help, just like with any other dog breed.
This is just a brief guide, its purpose is to give you some basic info as a potential pug owner. For some, it will be enough to change their mind about getting a pug, and that’s fine. Like I said, pugs are not for everyone. But if you still feel that you can do it, that pugs are the right breed for you, you are now more prepared. Good luck with your new friend!