Any tips?

if you're braindead,yes

Can I kill every monster I encounter or will I run out of ammo? I hate leaving shit alive.

Depends on the difficulty and how good you are at headshots.

are there spiders in thius game?

I'd probably just play on normal. Typically I don't play hard on my first go. As far as headshots who knows.

Mountain Climbing is normal difficulty, Not hard (they added a very easy difficulty).
"Alternate" controls destroy the game balance.
Jill has more inventory spaces
Chris has a significantly higher health
Try not to carry more than 1 gun unless you know you're gonna be going for a boss fight (you can be more lenient as Jill due to more inventory spaces).
You don't need to pick up every item as soon as you find it. Leaving herbs in well travelled hallways can help out.
You run slower with a big gun equipped (shotgun, grenade launcher), and faster with the knife or nothing equipped.
The knife is shit.
For your first run try to clear out the hallways, at least near the safe rooms.

>Should I use a guide?
No, you dumb fuck.
Why do you even ask such stupid shit??
Not to mention REmake is over 50% brand new game, just to keep even the veterans on the edge.

Yes.

Hard mode is not even accessible before you beat the game.
The initially available difficulties are (from top to bottom, in HD port):
>Normal
>Easy
>VERY Easy (new addition to 2014 ver)

knife them with the knife

Just played normal mode last year and it has more than enough ammo for you to 1-shot the zombies, but there isn't enough fuel for you to burn all the zombies.

>REmake is over 50% brand new game
You really shouldn't comment on games you've never played.