I don't think this post is kosher for this forum...
There is a buy/sell section but it is not public facing and most likely will not include real firearms... All the best but I would really recommend reading the FAQs before proceeding.
These are some better options, My apologies to the mods for including external links...
https://www.canadiangunnutz.com/
https://www.gunpost.ca/
https://firearmscanada.com/