First, you are going to need to download the app it cost $7.99. When it downloads, it will bring you to a screen that says "play". It will then bring you to a screen that says "back" in the left corner, and "new" in the right corner. When you click new, it gives you the option to name your world, and what game mode you want to choose. You can name your world whatever you would like. You can also choose the
survival or creative game mode.
Survival game mode allows you to gather supplies for yourself. You can gather wood, stone, iron, gold, red stone, lapis, and eventually diamonds. If you get to the point where you have accumulated three diamonds, you can collect obsidian with a diamond pick-axe to create a nether portal. If you collect five diamonds, you can create an enchantment table. By this point you will most likely have a house, farm, tools, and stuff like that. So basically, you are just surviving in a cool game.
The other game mode is creative mode. You can either have a flat world, an infinitive world, or an old world. In creative mode you already have an endless supply of everything in the game in your inventory. You do not have to collect everything it is already there for you. Creative is mainly really fun to build things in. You can also fly by double clicking the jump button. You can not die in creative mode it is impossible.
The goal of the game is to have fun. You are not controlled, you can do things the way you would like to. It is a game that can fit any personality. The fact that there are no rules makes it ten times more fun! Creative, adventurous, and fun that is all you need!