You build your own house and you can find NPC villages in the world
There is no such thing as 'straw' in Minecraft. So you can't.
you make a house with wood dirt leavs
There is no way to do it.
Light up your house and kill all the bats.
you can, but if your house is in the nether, your bed will explode
try a site called planet minecraft, there are lots of good minecraft resources there.
you can put up a sign that you can make out of wood and put it at the front of your house
You destroy it and walk away.
No, it's only available for download.
You can create a bathroom in your Minecraft house by building a big, roomy section in your house, preferably accessible from your bedroom. Now all you need are the bathroom furnishings.
you can only find a house in multiplayer or in singleplayer villages. why ask when you yourself can just build a house?
You can build your house anywhere you want in the world of Minecraft. One of the best places is to build where you first find coal. Also, try to build in a place that's flat.