Copper Ore is one of the new ores added by the Soul Forest Mod. Copper ore can be found in the overworld together with a few of the other Soul Forest Mod's ores. Copper Ore is a low tier ore and can be mined easily with a wooden pickaxe or better. It can usally be found in large veins underneath layer 100 in any overworld biome.
Copper Ore can easily be smelted into a Copper Ingot in a regular furnace.
The main purpose of copper is the crafting of bronze, as bronze is one tier higher then copper. A Bronze Ingot can be crafted in a regular crafting table combining 1 Copper Ingot with 1 Tin Ingot (Shapeless), you will then get 2 Bronze Ingots.
Even though you can easily craft Bronze Ingots using copper, copper can also be crafted into its own set of tools (before release 1.8 Copper Armour & Copper Sword are still in the Soul Forest Mod).
To craft a Copper Shovel, Copper Hoe, Copper Axe or Copper Pickaxe (or a Copper Sword aswell in the pre-1.8 Soul Forest Mod versions) you can just use the regular crafting recipes but instead of a normal "Iron Ingot" you use a Copper Ingot.
In pre-1.8 Soul Forest Mod you can also still craft a Copper Armour, to do that you also use the regular crafting recipe of every armour piece but instead of "Iron Ingots" you use Copper Ingots.