Good Morning Rama,
As you’ve likely discovered, there are a multitude of opinions on search engine optimization out there. That’s one of the reasons the WordPress core doesn’t attempt to handle it for users. So the way to take care of that is via a plugin.
There are bunches of them out there, but I’ve found Yoast SEO (https://wordpress.org/plugins/wordpress-seo/) to be quite good. It lets you enter a unique title and description for every page and post. It also has some useful reminders as you create content to help that page turn up in the searches for your keywords.
The main limitation of it’s evaluation tools is it can only check content that’s entered into the main content box of a page or post. If it’s entered via a widget or some other means, it can’t check the content there. That doesn’t mean that Google won’t be able to see and index it, just that the plugin can’t evaluate it.
If I had the time, I would create a new SEO plugin that evaluates the page as it’s rendered and not just based on the content entered into the content box.
The plugin will also make a site map for you. That will help create those additional sections below your main page in search results. As Google indexes your site, it’ll start to add those in over time.
Hope that helps out,
Bill