After you have chosen a topic, make a new page by creating a link below. When you have made the link, you can click it to create your new page.
Alternatively, you can add a new page (see bottom left of the page) and come back and link to it later.
Once you have your new page, start filling it with (relivant) information!
Don't forget copyright! No cutting and pasting. Acknowledge your sources of information with links to their website, etc.