There is no SEO guru anymore, in the old days, Google algo is not mature enough, there are so many tricks and methods to be exploited, thus so many people came up from the surface suddenly, they made quick and huge money and be called like a hero or even legendary SEO.
There are too many people can fall into that category, just too many, even too many hidden guys in this forum made millions in that wild western period, so you can't say who is guru who is not, because just too many in the old days, they all have their own stories and sharp eyes.
And for now, algorithm is mature enough, you can't rank good and make a lot of money without a lot of money to invest before that happen, and if you have money, you can beat any guru, just hire best quality writers, write best quality contents, buy best quality links, then you can rank anything.
But hell yeah, if you are really new to SEO, and want to learn sth very basic, some good places can be like - backlinko, gaps and details, niche pursuits, authority blogs from industry giants like ahrefs, semrush, moz blog, seo news from searchroundtable, SEjournal, just name a few.