How to deal with URL rewriting?

Okay, guys. I found URLs are not SEO Friendly. What now? Can anyone explain to me the URL rewriting process and the implementation of 301 redirection after that? I have not yet found a quality article on this topic, a lot of information is missing, if you have an interesting source, please share.

It's simple.

1) Download a 301 redirect plugin for wordpress
2) Change the URL and paste the old ones in a file
3) Create the redirects to the new articles

example:

OLD article: bhw.org/yes-sir-dear
NEW Article: bhw.org/you-should-say-hello-not-dear

301 redirect bhw.org/yes-sir-dear TO --> bhw.org/you-should-say-hello-not-dear

Here's what I use: https://wordpress.org/plugins/eps-301-redirects/