If you are jumping right into Minecraft without any prior knowledge it might be a bit confusing at first. Here is a really nice video tutorial that will teach you the basics of Minecraft.
Paul Soares on Youtube explains how to create tools like a workbench using blanks and then craft more stuff. Crafting is one of the key elements of Minecraft. You need to know how to craft tools like the pick or shovel (it’s quite simple once you know how it works) to get more materials to craft new items. You’ll create some fancy 8-bit swords to defend yourself against skeletons!
Currently there are 96 recipes to create new items. You can of course play around with the materials to come up with something, but there’s also a useful Minecraft Wiki with all the recipes for armors, weapons and all the good stuff.