@bruceaa Line and paragraph spacing are controlled by the theme. To change those, you'd have to change the CSS of the theme to adjust it. It's not something that you can change through the editor at all.
Publishing on the web isn't the same as writing a document in a document editor. Webpages are designed to have a certain look, and spacing of elements like text and such are controlled separately from the content itself. This concept is called "separation of presentation and content".
The WordPress editor really only allows you to change the content. Things like emphasis and strong (which show up as italics and bold, usually) are considered to be content. Things like fonts, line spacing, etc., are considered to be presentation. So to change the presentation, you have to modify the theme itself.