How would I have got blog and news pages to list articles/blogposts, how do I edit? I have a 'blog' page that lists blog posts and a 'news/events' page that lists articles.

I cannot remember how they got there, if they were automatically generated. I think I had to do something at least for the articles page, but I cannot find anything about why mysite.com/news lists all the articles and how mysite.com/blog lists blog posts. I've looked through structure and content and views and don't see where this is coming from and I have no hover in the admin interface to edit the whole page (just individual posts). These pages seem not to have any titles set, either.

The main concern here is in the menu right now they are absolute links and I want to be dynamic, relative paths.. but I don't know what to put for that. I also need to make sure they properly get an 'active' state in the menu, which currently they do not!
In Drupal 7, go to /admin/structure/menu/manage/ to manage your menus. Select "Main Menu" as that will probably be your primary navigation.

Click +Add Link. For both Blog and News, set the appropriate name in the "Title" field.

For path, set the Blog path to "blog" or for News you can set it to "home" to retrieve articles promoted to the front page, or something like "news" if you have a specific page with a path set to that for those articles to be displayed on.