The idea is mostly to increase the amount of Canadian and Canadian historical content on Wikipedia -- plus maybe "disrupting the Western, cis, white male dominated nature of Wikipedia content," though "anyone is welcome to participate," so it's complicated. But individuals and classes are invited to participate, there is scope both for group gatherings and online participation, and experienced Wikipedians are sought but total beginners welcome. The link above also provides its own link to basic instructions for drafting Wikipedia entries.
Go at it!
