There are 25 currencies currently in official use in North America, including currencies from countries which are not sovereign states or dependencies. The most common currency in North America is the United States dollar.
It is best to carry cash in various denominations as it eases transactions with smaller stores and businesses. You can also carry your debit or credit card as they are widely accepted in almost all the places including malls, hotels and tourist places.
Before your North America trip, make sure you get your exchange done so you do not have to worry about doing the same once you are in North America. Speak to SOTC before to get the best rates before your North America holiday.