In order to get metal in Terrafirmacraft, you will need to either find a vein of it in the ground, or smelt it from ore using a furnace. To find veins of metal, you will need to mine with a pickaxe until you find one. Once you have found a vein, you can then use your pickaxe to mine it and collect the metal. If you want to smelt ore into ingots, you will need to first place the ore in a furnace, and then use fuel such as wood or charcoal to heat it up. The process of smelting takes longer than mining veins, but allows you to collect more metal at once.