I would suggest a "long road" - forget for a while all this PHP stuff and invest some time "to know any better" and learn some theory to better understand hows

I would suggest a "long road" - forget for a while all this PHP stuff and invest some time "to know any better" and learn some theory to better understand hows and whys that will arise in daily practice. I suggest to take CS61A by prof. Brian Harvey (it is available on YouTube) and then with understanding of why something is better than other, take a look at Scala and Clojure as appropriate tools to get shit done. PHP is a dead end, and websites could be built with Scala or Clojure too. I wouldn't recommend Haskell before understanding deeply CS61A and SICP. HtDP2 and related course on Coursera is another decent start, but the path described above should be taken afterwards.