Once you have Bitcoin Gold (BTG) in your QuadrigaCX account, you will want to request a withdrawal. You can easily find the withdrawal button on the Dashboard page under your Bitcoin Gold (BTG) balance which will then prompt you to enter the amount of Bitcoin Gold (BTG) and wallet address you want to send them to. If you are actually trying to withdraw CAD then you would first have to first make a trade to sell your Bitcoin Gold (BTG) on the exchange.
Important: As noted on each currency's withdrawal page, do not send a different currency to another's address. i.e. do not send Bitcoin Gold (BTG) to a Bitcoin (XBT) address etc. If you make this mistake, there is nothing we can do.