In minecraft you can craft various blocks and items, some of which are only available by crafting them. To craft you simply place certain blocks and items in a crafting interface, which can either be the 2×2 crafting grid in your inventory or the 3×3 crafting grid of a crafting table. The crafting table has a larger grid, which allows you to create more items than on the inventory crafting grid.
Note that the position of the items in a crafting grid only matters to some extend. Most items require you to place the needed items in specific positions from each other, but you can mirror the positions and put them in different corners if the recipe is small enough. For example, a crafting table requires 4 wooden planks in a 2×2 square, but it does not matter in which part of the crafting grid you place this square, it can be in any corner.
Also note that any recipe which requires wood or wool can be made with any color of wood and wool. Different colors can even be mixed together. All recipes which require coal can also be made by using charcoal instead.