People use 'bad wordds' all around the world.

You have many Americans who can not say 6 words in a sentence unless 5 of them are swear words ( see the movie ' The Wolf of Wall Street ' if you don't believe me. )

On the other hand I know many many people who would never ever use a swear word, whether they were religious or not.

So we can not make blanket statements

It really depends on which Americans, and in what environment! You will find everything from people who never do to people who curse constantly. For example, when I worked on Wall Street people cursed all the time even at work, but in other occupations it might be very unprofessional. 

The differences between Canadian and American English are minor, though the accent is a bit different. It's similar to the relationship between English in England and American English - just a few key words are different.

I'm Canadian currently living in the US for the past few years. Nobody has ever asked me if I wasn't American based on the way I speak. So, to answer your question from firsthand experience, there are no major differences. Although, I will admit that Canadians do use 'eh' at the end of some sentences. It has the same meaning as 'huh' or 'what do you think' that American use. 

Example

American: "That's a funny movie, huh?!"

Canadian: "That's a funny movie, eh?!"

But if you ever want to know who is really Canadian, just ask what their favorite coffee shop is; if they say Tim Horton's , they're Canadian!

Canadians use a lot of ”Eh?" at the end of their sentences. Swearing is same mostly.

I think a lot of people get their impressions of American English from Hollywood films. I think these definitely contain more swearing than everyday English, perhaps because their contain more extreme situations than everyday life (fighting, outrageous situations, etc.), or might feature people from subcultures, like criminals. Note that some British movies and TV shows contain huge amounts of swearing as well.

As others have pointed out, how much a person swears is fairly independent of nationality, it depends more on your upbringing and who you hang out with.

I don't think swearing is necessarily "bad". Words like fat, ugly, stupid can be very "bad" if used to insult someone, but if a friend tells you "Wow! That meal you cooked was f***ing great!", it's a compliment! Me personally, I might use swear words if having a beer with a friend at a bar, but would never swear when talking to a stranger in a formal/neutral setting. It's a question of social setting: you wouldn't wear a swimsuit to the opera or a tuxedo to the beach, and swearing in the wrong social context is awkward too.

Knowing when you may and may not swear is subtle, so you're right to avoid it for now. Once you're very comfortable with the language you can decide whether or not to use swear words...and if you decide to never swear that's totally fine too.