You might be surprised when you get there as my only problem with Americans is the customs and immigration at LAX. I travel to the USA and Canada (Vancouver) frequently and the people, especially those in country areas of USA are very nice people.
Also, depending on what part of Canada you are going, but if Vancouver, instead of crossing at the Peace Arch which is the main crossing point and can sometimes take more than 45 mins to cross due to traffic etc, you might consider driving east along Canada 1 highway from Vancouver about 30mins, turn right into 264th Street (Aldergrove Bellingham Road) as the border crossing there invariably only has three or four vehicles before me when I cross. You then continue down 264th, which changes at the border to Guide Meridian Road (539th) to Bellingham, Seattle etc. Saves a lot of time.