Probably M1. Requires a Part 141 school and it must be SEVP certificated. A database of these schools is maintained by Homeland here
https://studyinthestates.dhs.gov/school-search
The M1 is available only to full-time students so requires attendance (not the same as dual instruction hours!) of 18 or 22 hours a week. Border commuter students are exempt from the minimum attendance requirement. Either way as a Canadian citizen no physical visa will be issued but you do need the I20 certificate.
The attendance requirement is also not applied if you are admitted to US with status in a different class, eg TN status (working as a NAFTA professional) or because you’re from an aboriginal group (
Jay Treaty), etc. See
the guide Nonimmigrants: Who Can Study? published by SEVP (pdf link).