I want to know in depth more about this game such as who does what and how. Who counters who and why. Why buy this and not that. Anyone who can mentor me greatly appreciative.

I don't know nearly enough to mentor, but it as well as the guides linked on these very forums, it might be worth your time to check out a site like mobafire.com. As well as general build ideas, there are plenty of very detailed guides that also link to or explain advanced concepts and how they relate to a champion, role or build.