Ministerial Orders refer to orders “created under the authority granted to a minister under a statute or regulation that are made by a Minister” as opposed to Orders in Council which are issued by the Governor General of Canada or the Lieutenant Governor of a province.
For that reason it’s generally harder to find Ministerial Orders than Orders in Council, although this depends greatly on the province. Some provinces, such as British Columbia, make all their Ministerial Orders available in one place. For other jurisdictions you may have to look specifically at the Ministry’s website to find the order (e.g. Transport Canada provides its orders here: https://tc.canada.ca/en/ministerial-orders-interim-orders-directives-directions-response-letters.)
One thing to keep in mind is that, depending on the jurisdiction, the same number may be used for multiple Ministerial Orders. Drew Yewchuk gives an example in a blog post: “there is an M.O. 20/2020 from the Minister of Environment and Parks and an M.O. 20/2020 from the Minister of Justice.”
(And just to confuse the matter further, both Ministerial Orders and Orders in Council may also be regulations which involves another numbering system.)