What would be your go-to guide for a tech engineer wishing to get into SEO?

Hello Reddit!

I am currently trying to improve the SEO and visibility of my https://get.mymfa.io website but it is particularly hard to find a proper "guide" to get websites on top of search results and sometimes I even end up reading contradictory information.

What would be your most important personal (and non-obvious) tip you would share if you wanted to get your new side project to reach the top search results?

Thanks a lot in advance for your help!

Jonathan