You're going to need a web host. No, you can't just install WordPress on your home PC and host the website from your living room!

Well, you could, but if you want to do that, please stop reading, leave now, and don't come back! Really! You can't host a decent website from your spare bedroom!

Seriously though, you need a reliable host with fast servers and lots of bandwidth. Web hosting is cheap and is a necessary barrier to entry in this game.