You can carry as much as makes sense in your inventory without tracking it. However, if you are carrying more than two bulky items you have zero Grit and are deprived.
Bulky items are heavy or awkwardly sized, requiring two hands to hold.
Armor (i.e. 1 Armor) subtracts its score from the result of damage rolls against you. Items, such as shields, that grant bonus armor only apply while the item is held (i.e. +1 Armor). You cannot have more than 3 Armor in total.
Single pieces of equipment that grant 2 Armor are rare, and usually carry some sort of drawback or limitation.
Ammunition (arrows, bolts, bullets, etc.) are generally not tracked and considered to be unlimited, unless specific circumstances would lead to it being in short supply.
Unique or specialty ammo is tracked individually where appropriate.