So I'm 21, and my friend, he is 17. We want to travel to Canada for a vacation, this would be an extended vacation of two weeks in Winnipeg. I do not have a passport. What would we need to travel to Canada by car?
Getting into Canada is pretty easy, eh. Getting back into the States is harder, and Canada won't let you in without the ability to get out.
You will need either a passport, enhanced driver's license, NEXUS card etc. Check any airline's website for details.
You will also need proof of ownership of the car. If it's yours, fine. If it's your parent's, it's much easier if the registered address matches your documentation's address, and the family name is the same. If it's "your friend's", expect rather long delays at both border crossings.
(rental cars are easy, just ask the rental company for the necessary documents. As you are under 25 getting a rental car is nearly impossible.)
And as a side note, why Winnipeg? It's hardly the vacation capital of the North, and the summer mosquitos are rather vicious. Unless you know people there, the middle part of Canada is rather bleak.