John Mueller of Google answered a question in a Reddit thread about advice on how an SEO noob, a person who is inexperienced in SEO, learn and get good at SEO. John said you should gain experience with the help of webmaster help forums and communities.
John wrote:
I know I'm biased, but for learning technical issues, there's not much that beats getting experience. One great way to get experience for cheap is to be active in any of the webmaster help forums / communities (Google has one, but there are others too). After a while, you can spot the common issues quickly: "page isn't indexed" -> "check meta tags, robots.txt, rel-canonical, etc.". Getting practice with other people's sites, even if you never post in the threads, helps you to be secure when a client comes to you with the same issue. When it comes to debugging issues, keep https://en.wikipedia.org/wiki/Occam%27s_razor in mind -- it's almost always like that :).
There is nothing like experience and often when you are new to something, hearing from those who have gone through things many times that you are for the first time experiencing is helpful. So many help forums can be, um, helpful. Of course, some people on forums can be pretty rough but still, sharing and learning online is a beautiful thing.
The thread is pretty nice to read so check it out.
Forum discussion at Reddit.