Many attendees will either need an Electronic Travel Authorization or a Visa. Find out if you need a Visa to visit Canada by filling out an easy questionnaire. http://www.cic.gc.ca/english/visit/visas.asp
The University of British Columbia has a number of short term stay options that can accommodate a range of budgets and requirements.
Things to do in Vancouver
Tourism Vancouver lists a wide variety of activities and attractions on their website.