First, you need get a licence from Vital Service Agent. In Vancouver even the insurance company can issue the marriage licence.
Second, You must hold your marriage ceremony within 3 months. This can be either a civil ceremony, or a religious one. No matter which one you should have at lease 2 witnesses.
You may refer http://www.vs.gov.bc.ca/marriage/howto.html.
The civil ceremory is more suitable for us. Check out a list of commissioners, then make an appointment with him. That's it. You can even go to his house to hold the ceremony.
Be aware of the marriage certificate. You can order rush service, then you can get it in one week.
Good luck to you.