Before you can begin mining in you will need to craft tools. This involves searching for raw materials and then turning them into materials which can be used to craft the tools. To do this you will first need to build a crafting using four planks of wood and then place it in your world. The next step is to craft a tool kit by using planks and sticks to make wooden pickaxes which you can then use to mine cobblestone. Once you have have enough cobblestone, you can then start crafting stone tools such as cobblestone pickaxes. Cobblestone tools will help you mine for coal, which you need to make torches. Below is a basic Crafting guide, for more indepth information click this link.