In general there are Title and Tagline
If you have there something than dont use SEO settings for homepage because it will rewrite it and there you will have what is in seo settings for home page.
Google and other search engines aren’t obligated to use your meta description. Sometimes will use sometimes will not..
If you need another titles and meta for your author page than you can write it there, if not it will be used default.
You don’t have to use templates, you can setup your titles manually. When you are editing posts under you have seo options and if you write there this will be used for your post (only this post not all) templates are to do some scheme for all posts.
Same can be for authors, tags…etc