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You already preempted the obvious answer, i.e. read more. I barely scratch the surface of discussions here, but I try to keep up. While you will quickly pick up the formulas for on-page and off-page SEO, reading here will give you the fine edge over others who have read articles or outdated books.
Of course, having access to one or more sites where you can try various theories is ideal. You will need to buy your own domains and get proper hosting. It is not a good idea to test theories on free sites.
To motivate yourself, get into affiliate marketing and SEO those pages. Good luck.
The point that I am making is that you definitely need to know the basics and understand the concept of SEO. After that, you really just need to apply it to the real world to see what works and what doesn't.