If you're looking for free coaching, You'll get what you paid for, is all I can say, What I suggest is setting up your own training routine, Yes without someone who actually knows what they're doing you'll be swinging blind, but its better than sitting stagnant. Research what you're curious about, Test it out on the rift. and then apply what you wish to retain. I don't mean to advertise, but I use skill capped, its just a bunch of videos but Instead of playing background music I listen to that. Or i'll open up old VODs of the LCS and listen to that.
I guess my conclusion is that, if you're looking for "free" coaching you're better off just Exploring the "wonders" of league of legends either by yourself or with some friends. Having some wanna be Plat V coach, who doesn't understand how to teach correctly isn't gonna benefit you, and may even harm your potential.
Sorry for the long ramble, I guess if they have an educational degree they maybe legit. :p