Iron first makes?
- shield if you use it
- mace or other weapon
rock cutter -> grinding wheel & forge upgrade (low cost upgrade)
a few nails (low cost comfort items, throne, unlocks big boat, more)
pickaxe: assuming you skipped bronze and just rotated 2-3 antler ones, this clears up the mess and is the best one you can get. Hold off on upgrades, but go ahead and make it so you can mine the iron easier.
and after that, if you are gonna, your suit of armor.
-- be sure to have 200+ spare iron ingots stored away after you are happy with your gear.
you will need them for:
- bigger chests, you can reclaim these when you upgrade to the final biggest chests
- additional crafting station upgrades.
- next 2 tiers of gear will use some iron. actually, a lot of iron.
- ironwood beams are critical for making tall builds / support heavy designs like rock ceiling.
and more.