Basics
"let's start at the start..."
The Animal Crossing series is at heart a simulation game concept with cutesy rural/animal flavor. Its world is highly open to exploration, and there's really no condition for "winning" per se--it's more about what you want to bring to the game, what you're interested in, and how you want to express yourself. Winning is subjective in Animal Crossing; how do you personally define success? Whatever you answered, you're likely to find it!
Beginning the Game
"history starts now..."
When you start playing any of the Animal Crossing series, your human character "moves into" the new town (which you get to name), and you are promptly given a new start thanks to the local shopkeeper, a friendly raccoon named Tom Nook. He graciously allows you to move into one of his small homes, provided you pay it off, and gives you a temporary "job" at his storefront, basically to help you learn the layout of your particular town, get familiar with how to talk to other animal villagers, and use items.
Once you're "done" with all his tasks, you are free to explore the new town, and to determine how to achieve whatever kind of experience you desire from the game! Let's take a closer look at all that this entails: