#1. Decide to invest just enough time to solve your specific goal and then move on to the next goal. DO NOT LEARN JUST TO LEARN (that's a hobby, not a business)
#2. Read Google's Guide on SEO https://support.google.com/webmasters/answer/7451184?hl=en
#3. Read this short article, it's the BEST SEO ARTICLE I HAVE EVER READ https://moz.com/blog/every-site-is-linkbait-linkerati-worthy
#4. Publish content that webmasters will WANT to link to (ie. it's genuinely useful for THEIR audience which ideally is YOUR audience as well)
#5. GET LINKS THAT WILL SEND YOU LEADS if you sell anything by picking up the phone and calling people or reaching out proactively somehow just as if it were sales itself you are doing.
#6. Choose keywords your prospects are using by looking at the Google's Keyword tool, and start out with longer tail phrases until you start noticing that you can rank for harder and harder ones
#7. Did I mention to avoid learning for the sake of learning? It's a black hole that will suck your life up with no return. Just learn what you need to know to solve the next problem directly in front of you and then move on :)