https://www.canada.ca/en/immigration-refugees-citizenship/services/come-canada-tool.html
So to answer your questions...
1. You can submit one application for both of them, as they are married.
2. Yes, there is a question that you are submitting the application on your behalf, so you fill out the questionnaire as if you are your father, and then at the end, there is a question if someone else is applying on your behalf, which is you.
Did you ever try the questionnaire yet? Nothing bad will happen from trying it.