I think you can probably find many of the answers to your questions here -
Business Start-Up Assistant - Home Page. It's the website run by the Canadian Government.
Regarding a trade license - that will depend on which provice you select to operate from. Actually the answers to many of your questions will depend on which provide you select to operate from.
You can also call the business service office directly. From my experience, the people there are pretty friendly and knowledgeable. Here's the information: 1-888-576-4444
(9:00 AM to 5:00 PM, in every time zone).