A continuity page exists for one thing, too coordinate all your work, to help you know which characters belong which story, items and a hub for all these pages, including the pages for the adventures you plan to write, since it would madness to put everything in the Main character's history section.
Here is the basic layout you should adopt, using my own as a basis.
First start with an Intro, note the page should say the Main character's name and the Continuity in brackets e.g Ultraman Orion (Continuity).
Note, this is note an introduction to anyone or the universe you are creating, this is just to explain to people and remind yourself the overall tone of your story, it doesn't even have to name any characters, so long as the ready understands what they are in store for.
This is just a list of Links to your adventures for easy access for readers and yourselves.
As before another way of keeping tabs on your work.
This section is for terms and objects that are unique to your own work or which slightly deviates from that of the Canon. For example you can list Ultras and state how those of your universe differ from those of the canon series. E.g. My Ultras do not have a time limit on Earth like worlds.