WP Address and Site URL ( multiple installations/blogs)

I’ve have 2 questions and wanted to post them both together because the answer to one may affect my understanding of the second question as well as the way I have installed WP…

1st Question: Website vs WP Address URL
I don’t understand the site url. I have several domains with one host. I had them install WP in [denisestokes.com] so the path to that folder is https://denisestokes.com/wordpress Do I leave the “WordPress Address URL” as is and change the “Site Address URL” to https://denisestokes.com if I want people to just use my url and land on my wp blog site? AND If this is the correct way to change it – what are my options to later add non-wp pages to my website?

2nd Question: Multiple Installations (keep url simple and
WP will later be installed for each domain I build a wp site for – and will also have a separate (new) SQL database for each domain installation of wp since I can have up to 7 SQL databases and am currently only using 2. This seems simpler to me so I can only mess up 1 blog at a time. Is this the correct way to continue building WP sites for my other domains while also keeping those wp urls and site urls staright?

Thanks for any help. You guys have the one of the most helpful forums I use!