Newbie trying to format newsletter posts

Hi, I am new to WP and so I am trying to figure out a complex formatting idea, but do not even know how to find what I am looking for (my terminology is lacking).

It is for a monthly newsletter, so I do want it to be a specific “post” type, so that I can just add new posts to the same page.

Here is what I would like the “post” type to look like:

–A unique post type that has a three column layout with the ability to have multiple boxes in each column that can be filled with content (text/image/video).–So it looks a little like a newspaper or flier–

–I am setting this up for users who have no coding experience, so it would be best if, in the backend, there were simply multiple content fields, and they could just fill in all the ones that they needed and the blank ones would not display (thus keeping them from having to use shortcodes, etc.)

Does this already exist? Is there a plugin? has someone created something similar and can share the process?

Thanks!