There are three main things that you must know about your website SEO:

• A technical part
  Content
  Link building (Use Linkreserchtools if you haven't got a clue what links are good for your site)

Check out this thread from Blackhatworld on how to create content, etc -- https://www.blackhatworld.com/seo/guide-full-example-of-how-to-do-on-page-seo.1251425/

It's from 2020, but still worth checking out.