Here on the east coast we have the Presidentials of the Northern Appellation Trail. In my youth I climbed many of them. I think I’ve hiked Mt. Washington 4 or 5 times by now. Also climbed in the Seara-Nevadas once, which is probably more like what you’re climbing.
Anyway, from what I gather about the hike here (and what they’re talking about is a hiking trail, not rock climbing), it’s possible that it isn’t as scary as it looks.
(What concerns me is that you’re taking rock climbing lessons, so you may not be taking the route they’re writing about.)
If this is indeed just a “Moderate” hike (see the last paragraph under hiking here), there could be some hands and feet scampering over some steep rocky/rooty parts (beware leaning back too far, your pack’ll topple you backwards), but more tramping up moderate inclines on switchbacks and ridge lines. Not much danger to fear besides fatigue and slipping on the ever present loose rubble.
Oh, and Grizzlies. (Don’t forget to make lots of noise.)
So, some general stuff about hiking:
The weight of your pack should be primarily on your waist strap, not your shoulders.
Wear layers. Be prepared for warmer and colder than you think.
Blisters suck! Get good hiking boots and break them in early and often.
Wear thick socks.
Bring moleskin to cover baby blisters before they become monsters.
And wet socks make blisters. Bring extra socks.
Don’t forget to hydrate. Running water trail side is usually very drinkable, and delicious.
Finding the perfect hiking stick is part of the fun. Do this before exiting the treeline. It gets the first notch once you’re back at base camp.
And look around. It’s beautiful. And it smells good too.
That’s just a sampling…
Boxy, did I leave out anything important?