There are many sources outside talking about SEO friendly post. Most of them will be like these.
- Create unique and useful content.
- Use your target keyword in title, and in the content
- Have images that contains your target keyword in the “alt” attribute.
- Have long content (minimum 400 words)
- Have proper structure such as heading, etc.
- Use semantic keyword in the content.
There are many suggestions out there. By the way, SEO is not only on-page. You may consider doing off-page SEO too.
I use rank math as WordPress plugin to help me create good SEO content.
Doing SEO friendly post start with keyword research, you may consider reading How To Do Keyword Research + 20++ FAQ to have better keyword research.
Hope it helps. You may follow me for more about SEO from a programmer point of view.