Crafting is the method of rearranging items to make many different things such as armor, tools, weapons, etc. When you open your inventory (by pressing e if you are on pc.) you will have a 2x2 crafting space. To make a bigger crafting space you will need to make a crafting table. You can make a crafting table by putting 4 wooden planks into all of the spaces in the 2x2 crafting space. For some items you can place them anywhere on the crafting grid and it will still work. For example a Fermented Spider Eye can have it's ingredients placed anywhere within the grid. Here is a complete list of recipes:

6 Basic recipes
23 Manufactured recipes
10 Transportation recipes
13 Tool recipes
3 Weapon recipes
4 Armor recipes
20 Mechanism recipes
13 Food recipes
20 Miscellaneous recipes
12 Dye recipes
4 Dyed Block recipes
9 Enchantment and brewing recipes
This totals to 137 Crafting Recipes, excluding Firework recipes.

Also if you don't know how to craft an item just keep trying, or you can look up the recipe for it. Hope this helped you guys. Later, and have a nice day. Remember to stay positive everyone!

- Your helpful member, OoBubblesoO