Adding specific posts to specific pages

I have been searching the forums for “adding posts to pages” but most of the responses are several years old.

I am about to begin building a site – which I’d like to do entirely through WP – for an organization with a variety of activities: Performance, gallery, workshops. They would like to have separate pages – each of which would behave like or look like a blog with several posts – for each of the activities (including separate pages for sub-activities). For example, they will have performance events 5 days a week, for each day they want to be able to list a month’s worth of activities, so we would have one page for Saturday Performances that will list everything this month, and then towards the end of the month, be updated to include what’s coming up next month.

I was thinking that in terms of the best structure (so that it can be updated by someone at the organization) would be to make all the entries as posts on the index.php page (which would only exist behind the scenes), and assign categories for each entry, which would then be “fed” to custom template pages for each category.

My questions:
1) Does this sound like the right approach? or should I consider setting this up as a multi-site installation, and having a “blog” for each “page”?

2) If this is the approach, will I need to create separate custom page templates for each category so that it will ask for only that category?

I prefer not to use a plug-in, unless someone thinks that is the best way to go (I have looked at both “posts-in-page” and posts-to-page”).

I have read the Codex for “A page of posts” (https://codex.www.ads-software.com/Pages#A_Page_of_Posts), but I was not planning on creating a child theme, so I’m a little confused about some of the code included on that page (for example this part:

twentyeleven_content_nav( 'nav-above' );
  while ( $list_of_posts->have_posts() ): $list_of_posts->the_post();

    // Display content of posts
    get_template_part( 'content', get_post_format() );

  endwhile;
  twentyeleven_content_nav( 'nav-below' );
  ?>

Any thoughts and/or help would be appreciated. It may be that I am thinking too hard, and just have to start building, but am hoping for some guidance.

Thanks very much.