Read “SEO Starter Guide: The Basics | Google Search Central”
First, read “SEO Starter Guide: The Basics | Google Search Central” which is google writes to understand what SEO is.
https://developers.google.com/search/docs/fundamentals/seo-starter-guide
Choose WordPress Theme
Install SEO Plugin
Install SEO Plugin for WordPress depending on WordPress themes.
- Yoast SEO
- All in one SEO Pack
- etc…
Yoast SEO
All in One SEO Pack
Make Index for pages
How to Optimize Your WordPress Site for Search Engines