Blessing of Frost

If Blessing of Frost is copied, no mana was spent to cast the copy, so no +1/+1 counters will be distributed. You may still draw cards if your creatures are large enough.

The Kaldheim set doesn’t have any cards with mana costs that include {S}, but some previous sets do. If an effect says such a spell costs {1} less to cast, that reduction doesn’t apply to any {S} costs. This is also true for activated abilities that include {S} in their activation costs and effects that reduce those costs.

The {S} symbol is a generic mana symbol. It represents a cost that can be paid by one mana that was produced by a snow source. That mana can be any color or colorless.

Snow is a supertype, not a card type. It has no rules meaning or function by itself, but spells and abilities may refer to it.

Because none of the creatures are targeted, you can choose to put +1/+1 counters on a creature with protection from green, for example.

Snow isn’t a type of mana. If an effect says you may spend mana as though it were any type, you can’t pay for {S} using mana that wasn’t produced by a snow source.