Help to have more control of indentation and line breaks in text paragraphs?

Thanks in advance for any help with my issue. I’m still learning WordPress and I have a personal literary magazine-type site that publishes both poetry and prose. As such, formatting beyond the Advanced Editor Tools (previously TinyMCE Advanced) is important. Specifically, I need more control over these elements in my blog posts:

1. line breaks,
2. indentation of specific lines but not others, and
3. inserting spaces between some paragraphs but not others

Pretty much the basic line formatting you would find in any printed book of the last few hundred years.

I use an Uncode theme that I believe disables Gutenberg and its Verse block. (I only see the option to create Uncode’s proprietary Content Blocks.) I’ve inserted the CSS from the r/wordpress post linked here, which is helpful to indent the first line of EVERY paragraph on my site, but it also indents text in my buttons, and I need the control to make some first lines unindented or with multiple indentations (in poetry, for example). I’ve installed the only “poetry formatting” plug-in I can find, called Lineate, but its functions are somewhat at odds with the CSS code.

The link provided here is an example post that I’m trying to fix. Any help with code, plug-in recommendations, or anything else that would help me reach the goals in that numbered list above would be appreciated.

The page I need help with: [log in to see the link]