Buying and Selling Cars Work and Travel

As I will be in Canada for 6,5 months, 4 months of working, 2,5 months of travelling, I am thinking about buying a used car for my time in Canada to be more flexible and save some costs for rental cars during my travelling time. But I am a bit concerned by two things:

1. I want to buy the car in British Columbia and sell it in Ontario, are there any problems?

2. How much time should I plan for the selling process?

Thanks in advance.