A central concern for your legal research will be to determine if any statutory provisions apply, including both the statutes themselves as well as applicable regulations.
Often your research using commentary sources, or case law, will draw your attention to relevant legislation.
To find the statutes and regulations themselves, use The Canadian Legal Information Institute (CanLII).
Many annotated versions of statutes are published, which include commentary on the legislation. Check the Library Catalogue for to see if an annotated version of a particular piece of legislation is available.
If a treaty applies to your research scenario, you'll likely be alerted to it through your review of commentary literature. To find the treaty itself, try the following sources: