The best search tool for finding library materials is Summon, the main SEARCH box on the Libraries' homepage. It searches most of the Libraries' collection, all at once. It is great for finding any topic to do with Canada.
Summon works a lot like Google or other search engines in that you don't need to know any fancy search strategies. Simply begin by typing in a few words that describe what you're looking for. If you're not happy with your search results, try changing your search words, or try some of the search filters.
Because there currently is no access to the Library building and its print materials, you will want to focus on accessing ONLINE materials, that can be accessed through your computer. Look for items with an orange flag -- those are items that are available online.
The library also has other databases that contain Canadian content. You can explore them, as well as their descriptions, here.
The Canadian Encyclopedia is a good resource to explore if you're trying to pick a topic to write about. If you are having difficultly deciding what to research, you can browse it for everything from sports, history, famous Canadians, culture, Indigenous peoples, and more!