Edit: All of what I wrote below is still true, but it looks like the whole O'Brien tree has been duplicated (I noticed this while adding people to the Bay Bulls Category). I'm afraid you're going to get a crash course in the wonderful WikiTree 'merge' process. If you have any questions about how to do all the merges I'm proposing, feel free to send me message.
I couldn't find exactly what you're looking for, but in my experience, it always helps to go slowly, look for sources and add them to profiles, and build up the branches of your family tree. I hope you don't mind, but to help you get started I added some sources, categories, and links to space pages to Cornelius and Margaret's profiles.
I created the category for Bay Bulls. Categories are a good way to organize groups of people (from the same place, for instance). I also made the Bay Bulls town page. This can be a place that you add resources, or details about early families. If you notice, there's already a link to the Town of Bay Bulls genealogy website, that might be useful to you.
Hope that helps your research!