Let me start off by saying I'm extremely stubborn, but the only thing that I am more than I am stubborn is a lover of this genre of game, so I've decided to bite the bullet and ask for help. I play old school mode, and so I don't have an easy indicator of places I haven't been, but I've spend hours scouring every bit of area I can think of. I currently have a couple unsolved mysteries, but if one of you gurus can just point me in the next direction, that would be great. I have finished 2 elemental orbs and placed them on their pedestals, I've seen the head in the forest across from the weird stone golem (nooo idea on "this is another way out"), don't get "I saw where the meteor fell" but i figure that's a treasure. I don't know if I got the "silent one and his friend" clue, and there's what looks like a plate chest-piece behind a gate at the entrance to the "pillar of tranquility" or whatever dungeon. Finally, I know the snakes can be awakened...but no matter how hard I try I can't wake them up

help? I also saw the sign AR E. UHU etc, and I get that they stand for things but I don't know what yet. Thanks, sorry for the block but I really am afraid to look around because of spoilers. I really want to play this game, been stuck for hours and haven't touched it in weeks.
Edit: I didn't look at the spoilers for all the things people responded to here, but I thought I'd clarify, I've been through the ruins of desarune, only thing I think I've missed is a high treasure chest (probably just a secret button) but I got the gem of power...I'm sort of just looking for a nudge if I should keep going back down there (thanks for the chest-piece tip though! so helpful to skip the skyway too)