Ah, a cubic world made in front of your eyes, rivers full of azure blue water, the many animals that roam the land in peace and the green trees make you sigh. But danger lurks at night so you must better get prepared for the night, at night monsters from the depths would arise and you must survive.

First of all you need to make a crafting table, a crafting table would help you make all the objects you would need, simply find a tree(Any one would do) and chop it down with your bare hands, then chop down 3 more trees before making your crafting table.

Once you got your table, simply craft a wooden pickaxe, axe, sword with help from Minecraft Wiki which is the wiki for Minecraft on the internet. Set up your mine by digging a staircase down until you hit stone, mine around 30 blocks of stone and start building a simple shelter.

You would first like to chop down two more trees, make a furnace and stone tools, you should either find a good hill and dig  a little shelther with a little hole in front or build a 5x5 dirt house with some wood in it. You should focus on surviving the night.

Your hunger will go down so you will need some food to survive, so you should kill some chickens as they are easy to kill or cows,sheep,pigs and rabbits. You could try to get an apple from a tree but it is very rare. If you still have time then mine some coal from the underground.

The moon has risen, and the monsters have come out, you should get your sword and whatever food you have and kill the monsters with your stone sword. When your health is very low, either eat some food, switch to peaceful or hide in your shelter. You will get experince points that will help level you up for later reasons from the monsters. Different monsters drop different loot, zombies will drop rotten flesh and sometimes carrots, potatoes and feathers and even rarer armour if it is wearing armour. Skeletons will sometimes wear armour and will atttack by using bows and arrows, they drop arrows, bones and rarley armour and bows. Creepers will drop gunpowder as they can explode in front of your face while spiders will drop string and rarley a spider eye which can be eaten or turned into something useful. Enderman can teleport and will not attack you unless you look at them, they drop ender pearls. 

When it turns day, there will be less monsters, zombies and skeletons will burn to death, creepers will slowly despawn,spiders will become netural and the endermen are even rarer to be seen.

Head down and mine some more rare ores, first mine some iron to make a bucket and upgrade your tools, then you can mine rarer ores like redstone which can help you in making machines, gold which has many uses, emearlds which are very rare but can be used to trade with NPC villagers( Located in NPC villages, they can be very rare) and diamonds the most useful ore ever and so OP.

If you have already got tired of your old house, make a newer house by looking at tutorials on youtube or make a simple wood 15x15 3 floor house. You should also get a hoe and hoe the land, get your bucket and fill it up with water from the nearest water source and then arrange it in a 10 block long 1 block wide trench, make 3 of those and then hoe the land around it and use seeds from grass to plant them. If you have potatoes and carrots, you could plant them or beetroots which you can plant too. Pumpkins can randomly spawn and you can use them to plant pumpkins although you have to clear some space for them as the pumpkins will grow one block from the stem. It is the same for melons but melons are hard to find and can only be found in dunegons.

If you have got some iron and redstone, make a compass, and if you have gold and redstone, make a clock, these would help you to tell if it is night and day in a mine or locate your spawn point. If you also have a diamond pickaxe, find some obsidian which is next to water and lava which can burn you and mine it. Arange them in a portal formation and go into the nether portal.

What happens next, you choose.