Your application cannot be processed in Canada and must be send either to your home country's visa office or to a US visa office for processing.
Also, it can be more difficult to be approved since you won't be able to demonstrate strong ties to your home country if you are already in Canada. Best to apply from your home country.
In your case the review of you family and the fact that you Venezuelan will keep being an issue. It is assumed that anyone arriving from Venezuela may be looking for asylum.
