Terraria wikipedia

Part 1: Building

You will need to build a house for N.P.Cs to move in. N.P.Cs will sell you items needed for the game. For something to count as a house your house needs to be six blocks high and ten blocks long. It also needs to have a table, a chair and a light source.

After your first house is built the Guide will move in. He will help as you move on in the game. Many N.P.Cs will move in to your world. Many will also die or leave. To make sure they won't die your house needs to be strong and protected.

Remember you can always think and build big! There are no limits to what you can make.

That is it for part one.