I read somewhere that I would need “Certificate of non-impediment to marriage abroad” as a Canadian citizen
You'll have to check for India. Canada has an issue with providing these because federalism. There is a way to get in Canada before you depart, I'm not familiar, but my impression is that it is a huge PITA (serach that acronym if not familiar).
Most common is to get it at the Canadian embassy/high commission/consulate. You show up and they provide you with .... something similar (basically you swear in front of a Consular officer that there are no impediments to you marrying). With an appointment this can be done in half an hour - obviously if you are in a city with a consulate.
But after that the details vary by country - that document (stamped by the embassy/consulate) may need to be translated, accepted by the foreign ministry or justice ministry or something similar, then taken to the civil registry or similar, or or or.
While the process is not exactly the same for the USA, it is the same basic problem, so USA oriented resources (or Oz or NZ)
may give you an idea where to look / what you have to do. One big difference is USA participates in Hague Convention (an agreement about recognizing official documents),. but Canada doesn't (because federalism). Beware that anything that refers to an
apostille is not something we do.