Just don't use shotguns or a shield because those are "For noobs"
People who say stuff like that are just rustled that they lost. The proper response to such behavior is to talk shit and rub it in their faces. If you're going to play a competitive game without matchmaking (Elo, etc.), play to win. If that means reading guides or using OP things, so be it. With match-made games you can afford to relax because you play against people just as bad as you, and you can start try-harding at your leisure (don't let anyone tell you that's not the reason you're bronze).
In any case, if you don't play to win, don't complain when you lose. Because people WILL laugh at you. And seriously, why would you want to call someone who killed you a "noob?" I never understood that, denigrating someone who just proved they are superior to you.
Its not that I'm willing to go that far to enjoy a game... the fact is if I'm interested enough in a game/currently playing it, I'm naturally inclined go out of my way to look up a whole bunch of things on it in my freetime/not at home playing it time. Or at least look up things during gameplay when I don't know wtf something is about and/or for clarification.
This. You don't play to win in order to enjoy the game, you play to win
because you enjoy the game. Why else would you be playing it in the first place?
At what point does LoL hide stuff from you?
The enemies are building HP and you are a physical damage dealer. This is something you need to read a guide for.
It's really not. The recommended items are generally quite effective (though you'll still need to exercise
some discretion in deciding which, among that small handful, to build, and in what order), and HP stacking is really the easiest defense to deal with, conceptually. There's only like 2 items (BoRK and the thing that builds out of Haunting Guise) that even deal %HP damage, and straight damage is a generally effective way to deal with HP stacking. There's no debate about whether you need armor penetration or not; you just build MORE DAMAGE. How is that difficult, especially when the recommended items will tell you what to build? I believe there are even tips on the recommended items list telling you what each item is good for, e.g. Triforce's famous "tons of damage."
There are a lot of things in LoL that are obscure without a guide/coach to teach you, but dealing damage (the simple numbers, not counting intangibles like positioning) is one of the most obvious. It's simple attrition, and the numbers are exposed for all to see.